diff --git a/lib_com/options.h b/lib_com/options.h
index 1ab8d2b4256dae8747722ceeacb7beff6f93a3e9..f7f4bc74e4a7c6207548663c4f4332e8e4650d35 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -178,6 +178,7 @@
 #define NONBE_1200_ISM_JBM_BRATE_SW_FLUSH               /* VA: issue 1200: fix bug in renderer flush in ISM JBM bitrate switching */
 #define NONBE_FIX_1205_TD_STEREO_MOD_CT                 /* VA: fix mismatch of coder_type (mod_ct) btw. TD stereo encoder and decoder */
 #define NONBE_1203_MDCT2DFT_SWITCHING                   /* VA: issue 1203: fix severe artifacts during MDCT to DFT stereo switching when MDCT ITD is not used */
+#define NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH             /* VA: issue 1220: fix bug in renderer flush in OMASA 1ISM JBM bitrate switching */
 
 /* ##################### End NON-BE switches ########################### */
 
diff --git a/lib_dec/ivas_jbm_dec.c b/lib_dec/ivas_jbm_dec.c
index e1e29265fde8a710c7113f37090badbdaa65ea38..462ee2ad329431b6d67b3c0f6c18a8b8b53d7343 100644
--- a/lib_dec/ivas_jbm_dec.c
+++ b/lib_dec/ivas_jbm_dec.c
@@ -1517,7 +1517,11 @@ ivas_error ivas_jbm_dec_flush_renderer(
         {
             if ( ism_mode_old == ISM_MASA_MODE_DISC )
             {
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+                float *tc_local[MAX_NUM_OBJECTS];
+#else
                 float *tc_local[MAX_TRANSPORT_CHANNELS];
+#endif
 
                 for ( ch_idx = 0; ch_idx < st_ivas->nchan_ism; ch_idx++ )
                 {
@@ -1525,6 +1529,12 @@ ivas_error ivas_jbm_dec_flush_renderer(
                     mvr2r( st_ivas->hMasaIsmData->delayBuffer[ch_idx], tc_local[ch_idx], st_ivas->hMasaIsmData->delayBuffer_size );
                 }
 
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+                if ( ( error = ivas_td_binaural_renderer_sf( st_ivas, p_output, hTcBuffer->n_samples_granularity ) ) != IVAS_ERR_OK )
+                {
+                    return error;
+                }
+#else
                 if ( st_ivas->nchan_ism > 0 )
                 {
                     if ( ( error = ivas_td_binaural_renderer_sf( st_ivas, p_output, hTcBuffer->n_samples_granularity ) ) != IVAS_ERR_OK )
@@ -1541,6 +1551,7 @@ ivas_error ivas_jbm_dec_flush_renderer(
                     st_ivas->hTcBuffer->slots_rendered += 1;
                     st_ivas->hTcBuffer->subframes_rendered += 1;
                 }
+#endif
             }
         }
         else if ( st_ivas->ivas_format == SBA_ISM_FORMAT )
diff --git a/lib_dec/ivas_objectRenderer_internal.c b/lib_dec/ivas_objectRenderer_internal.c
index 269f7a0fbde8ddc6e7bdb22568f5ab89e8e08d92..2a4e7782da0647be7768eea9ab870e3c438e3492 100644
--- a/lib_dec/ivas_objectRenderer_internal.c
+++ b/lib_dec/ivas_objectRenderer_internal.c
@@ -99,11 +99,15 @@ ivas_error ivas_td_binaural_renderer_sf(
     int16_t nchan_ism_internal, nchan_ism, ch_offset;
 
     /* Set the number of ISMs */
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+    if ( st_ivas->ivas_format == MASA_ISM_FORMAT || ( st_ivas->ivas_format == MASA_FORMAT && st_ivas->nchan_ism > 0 ) )
+#else
     if ( st_ivas->ivas_format == MASA_ISM_FORMAT )
+#endif
     {
         nchan_ism_internal = st_ivas->nchan_ism;
         nchan_ism = st_ivas->nchan_ism;
-        ch_offset = 2;
+        ch_offset = CPE_CHANNELS;
     }
     else if ( st_ivas->ivas_format == SBA_ISM_FORMAT )
     {
diff --git a/lib_dec/ivas_omasa_dec.c b/lib_dec/ivas_omasa_dec.c
index 3bdb2e0c76e9a70b059666b74792cb436caefb66..c6731720441adb72f2597e93e0a97d7c8c4b806e 100644
--- a/lib_dec/ivas_omasa_dec.c
+++ b/lib_dec/ivas_omasa_dec.c
@@ -748,14 +748,26 @@ ivas_error ivas_omasa_dirac_td_binaural_jbm(
 )
 {
     int16_t n;
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+    float data_separated_objects[BINAURAL_CHANNELS][L_FRAME48k];
+#else
     float data_separated_objects[MAX_NUM_OBJECTS][L_FRAME48k];
+#endif
     ivas_error error;
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+    float *p_sepobj[BINAURAL_CHANNELS];
+#else
     float *p_sepobj[MAX_NUM_OBJECTS];
+#endif
     int16_t slot_idx_start;
 
     slot_idx_start = st_ivas->hSpatParamRendCom->slots_rendered;
 
+#ifdef NONBE_1220_OMASA_JBM_BRATE_SW_FLUSH
+    for ( n = 0; n < BINAURAL_CHANNELS; n++ )
+#else
     for ( n = 0; n < MAX_NUM_OBJECTS; n++ )
+#endif
     {
         p_sepobj[n] = &data_separated_objects[n][0];
     }
@@ -806,6 +818,7 @@ ivas_error ivas_omasa_dirac_td_binaural_jbm(
         {
             return error;
         }
+
         for ( n = 0; n < BINAURAL_CHANNELS; n++ )
         {
             v_add( output_f[n], p_sepobj[n], output_f[n], *nSamplesRendered );