diff --git a/lib_com/options.h b/lib_com/options.h
index 48b031d6041b16ac07682357ebc33e964c6b5db1..121cdad56d505faa0d2e7aa177a759fd0cfd9c89 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -177,7 +177,7 @@
 #define NONBE_1244_FIX_SWB_BWE_MEMORY                   /* VA: issue 1244: fix to SWB BWE memory in case of switching from FB coding - pending a review by Huawei */ 
 #define NONBE_1122_KEEP_EVS_MODE_UNCHANGED              /* FhG: Disables fix for issue 1122 in EVS mode to keep BE tests green. This switch should be removed once the 1122 fix is added to EVS via a CR.  */
 #define NONBE_1328_FIX_NON_LINEARITY                    /* VA: Fix possible issue when computing bwe_exc_extended and previous frame were almost 0  */
-
+#define NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING         /* FhG: Fix assert being hit in JBM code during rate switching */
 /* ##################### End NON-BE switches ########################### */
 
 /* ################## End DEVELOPMENT switches ######################### */
diff --git a/lib_dec/ivas_ism_dec.c b/lib_dec/ivas_ism_dec.c
index 6e46c4b89d73bcc378a4d55843d62ac47b2bfebf..000b5f6ca558610e4b77dc4024517796ec1c8c0a 100644
--- a/lib_dec/ivas_ism_dec.c
+++ b/lib_dec/ivas_ism_dec.c
@@ -128,6 +128,25 @@ static ivas_error ivas_ism_bitrate_switching_dec(
         mvs2s( st_ivas->hSpatParamRendCom->subframe_nbslots, st_ivas->hTcBuffer->subframe_nbslots, MAX_JBM_SUBFRAMES_5MS );
     }
 
+#ifdef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
+    /* JBM: when granularity goes down (e.g. Discrete ISM with TD Obj Renderer -> ParamISM with binaural fastconv
+        render what still fits in the new granularity */
+    tc_granularity_new = ivas_jbm_dec_get_render_granularity( st_ivas->renderer_type, RENDERER_DISABLE, st_ivas->hDecoderConfig->output_Fs );
+
+    if ( tc_granularity_new < st_ivas->hTcBuffer->n_samples_granularity )
+    {
+        /* flush already done in IVAS_DEC_ReadFormat() */
+    }
+    /* JBM: when granularity goes up set samples to discard at the beginning of the frame */
+    else if ( tc_granularity_new > st_ivas->hTcBuffer->n_samples_granularity )
+    {
+        if ( ( error = ivas_jbm_dec_set_discard_samples( st_ivas ) ) != IVAS_ERR_OK )
+        {
+            return error;
+        }
+    }
+
+#endif
     if ( st_ivas->ism_mode != last_ism_mode )
     {
         /* EFAP handle */
@@ -295,7 +314,9 @@ static ivas_error ivas_ism_bitrate_switching_dec(
     tc_nchan_tc_new = ivas_jbm_dec_get_num_tc_channels( st_ivas );
     tc_nchan_allocate_new = tc_nchan_tc_new;
     tc_nchan_full_new = tc_nchan_tc_new;
+#ifndef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
     tc_granularity_new = ivas_jbm_dec_get_render_granularity( st_ivas->renderer_type, RENDERER_DISABLE, st_ivas->hDecoderConfig->output_Fs );
+#endif
 
     if ( st_ivas->ism_mode == ISM_MODE_PARAM && ( st_ivas->renderer_type != RENDERER_MONO_DOWNMIX && st_ivas->renderer_type != RENDERER_DISABLE && st_ivas->renderer_type != RENDERER_BINAURAL_PARAMETRIC && st_ivas->renderer_type != RENDERER_BINAURAL_PARAMETRIC_ROOM ) )
     {
diff --git a/lib_dec/ivas_masa_dec.c b/lib_dec/ivas_masa_dec.c
index 6886d550a88be0c29f38b1925c5779c33ac351b4..5f4634c3836e01cb346f663b285579919395d073 100644
--- a/lib_dec/ivas_masa_dec.c
+++ b/lib_dec/ivas_masa_dec.c
@@ -1509,6 +1509,25 @@ ivas_error ivas_masa_dec_reconfigure(
                     tc_nchan_to_allocate = 2 * BINAURAL_CHANNELS;
                 }
             }
+#ifdef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
+            if ( st_ivas->ivas_format == MASA_ISM_FORMAT && st_ivas->renderer_type == RENDERER_BINAURAL_PARAMETRIC && st_ivas->ism_mode == ISM_MASA_MODE_DISC )
+            {
+                if ( n_samples_granularity > st_ivas->hTcBuffer->n_samples_granularity )
+                {
+                    if ( ( error = ivas_jbm_dec_set_discard_samples( st_ivas ) ) != IVAS_ERR_OK )
+                    {
+                        return error;
+                    }
+                }
+            }
+            else if ( st_ivas->renderer_type == RENDERER_BINAURAL_PARAMETRIC && st_ivas->ism_mode != ISM_MASA_MODE_DISC )
+            {
+                if ( n_samples_granularity < st_ivas->hTcBuffer->n_samples_granularity )
+                {
+                    /* flush already done in IVAS_DEC_ReadFormat() */
+                }
+            }
+#endif
         }
         else if ( st_ivas->nchan_transport == 1 && ( st_ivas->renderer_type == RENDERER_DIRAC && st_ivas->hDirACRend->synthesisConf == DIRAC_SYNTHESIS_GAIN_SHD ) )
         {
diff --git a/lib_dec/ivas_mct_dec.c b/lib_dec/ivas_mct_dec.c
index 84bf52456d17ed8c792100c0a10a3a2d7ada565d..2ea644dbd2abee742ddd2c43aa5da719557d0bf8 100644
--- a/lib_dec/ivas_mct_dec.c
+++ b/lib_dec/ivas_mct_dec.c
@@ -795,6 +795,25 @@ static ivas_error ivas_mc_dec_reconfig(
         }
     }
 
+#ifdef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
+    /* JBM: when granularity goes down (e.g. MCT with CREND -> ParamMC with binaural fastconv
+           render what still fits in the new granularity */
+    tc_granularity_new = ivas_jbm_dec_get_render_granularity( st_ivas->renderer_type, RENDERER_DISABLE, st_ivas->hDecoderConfig->output_Fs );
+
+    if ( tc_granularity_new < st_ivas->hTcBuffer->n_samples_granularity )
+    {
+        /* flush already done in IVAS_DEC_ReadFormat() */
+    }
+    /* JBM: when granularity goes up set samples to discard at the beginning of the frame */
+    else if ( tc_granularity_new > st_ivas->hTcBuffer->n_samples_granularity )
+    {
+        if ( ( error = ivas_jbm_dec_set_discard_samples( st_ivas ) ) != IVAS_ERR_OK )
+        {
+            return error;
+        }
+    }
+
+#endif
     if ( st_ivas->mc_mode == MC_MODE_MCT )
     {
         st_ivas->nchan_transport = ivas_mc_ls_setup_get_num_channels( ivas_mc_map_output_config_to_mc_ls_setup( st_ivas->transport_config ) );
@@ -1303,7 +1322,9 @@ static ivas_error ivas_mc_dec_reconfig(
         tc_nchan_tc_new = ivas_jbm_dec_get_num_tc_channels( st_ivas );
         tc_nchan_allocate_new = tc_nchan_tc_new;
         tc_nchan_full_new = tc_nchan_tc_new;
+#ifndef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
         tc_granularity_new = ivas_jbm_dec_get_render_granularity( st_ivas->renderer_type, RENDERER_DISABLE, st_ivas->hDecoderConfig->output_Fs );
+#endif
 
         if ( st_ivas->renderer_type == RENDERER_BINAURAL_PARAMETRIC || st_ivas->renderer_type == RENDERER_BINAURAL_PARAMETRIC_ROOM || st_ivas->renderer_type == RENDERER_STEREO_PARAMETRIC )
         {
diff --git a/lib_dec/ivas_sba_dec.c b/lib_dec/ivas_sba_dec.c
index abeb19243d216eebc158c4bbbcfc79f0812e9a6a..a11fb37d54e1495508fa719d06ea1b55f179efa4 100644
--- a/lib_dec/ivas_sba_dec.c
+++ b/lib_dec/ivas_sba_dec.c
@@ -173,6 +173,27 @@ ivas_error ivas_sba_dec_reconfigure(
         /* determine new granularity */
         granularity_new = ivas_jbm_dec_get_render_granularity( st_ivas->renderer_type, ivas_renderer_secondary_select( st_ivas ), st_ivas->hDecoderConfig->output_Fs );
 
+#ifdef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
+        /* flush renderer on granularity change form 5ms to 1.25ms, again only possible for binaural rendering */
+        if ( granularity_new < st_ivas->hTcBuffer->n_samples_granularity )
+        {
+            /* flush already done in IVAS_DEC_ReadFormat() */
+        }
+        else if ( granularity_new > st_ivas->hTcBuffer->n_samples_granularity )
+        {
+            if ( ( error = ivas_jbm_dec_set_discard_samples( st_ivas ) ) != IVAS_ERR_OK )
+            {
+                return error;
+            }
+
+            /* make sure the changed number of slots in the last subframe is not lost in the following steps */
+            if ( st_ivas->hSpatParamRendCom != NULL )
+            {
+                st_ivas->hSpatParamRendCom->subframe_nbslots[st_ivas->hSpatParamRendCom->nb_subframes - 1] = st_ivas->hTcBuffer->subframe_nbslots[st_ivas->hTcBuffer->nb_subframes - 1];
+            }
+            st_ivas->hSpar->subframe_nbslots[st_ivas->hSpar->nb_subframes - 1] = st_ivas->hTcBuffer->subframe_nbslots[st_ivas->hTcBuffer->nb_subframes - 1];
+        }
+#else
         if ( granularity_new > st_ivas->hTcBuffer->n_samples_granularity )
         {
             /* make sure the changed number of slots in the last subframe is not lost in the following steps */
@@ -182,6 +203,7 @@ ivas_error ivas_sba_dec_reconfigure(
             }
             st_ivas->hSpar->subframe_nbslots[st_ivas->hSpar->nb_subframes - 1] = st_ivas->hTcBuffer->subframe_nbslots[st_ivas->hTcBuffer->nb_subframes - 1];
         }
+#endif
     }
 
     /* save old */
diff --git a/lib_dec/lib_dec.c b/lib_dec/lib_dec.c
index 0e04971fc390a79cb44ed93ef9629b80dfa555e7..41feeafec2cb0add778f6379f96d2170430007a7 100644
--- a/lib_dec/lib_dec.c
+++ b/lib_dec/lib_dec.c
@@ -1080,6 +1080,7 @@ ivas_error IVAS_DEC_ReadFormat(
                     return error;
                 }
             }
+#ifndef NONBE_1321_JBM_ASSERT_BITRATE_SWITCHING
             /* when granularity goes up, discard samples at the beginning of the frame */
             else if ( tc_granularity_new > st_ivas->hTcBuffer->n_samples_granularity )
             {
@@ -1088,6 +1089,7 @@ ivas_error IVAS_DEC_ReadFormat(
                     return error;
                 }
             }
+#endif
         }
     }