diff --git a/lib_com/options.h b/lib_com/options.h
index 6b2998e3de454d0963569468fb349da4d42883b4..142e1ea7106465cc02b45fbc2338569a5a8b61a5 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -185,6 +185,7 @@
 #define NONBE_FIX_991_PARAMBIN_BINARY_HRTF              /* Nokia: issue #991: fix using of binary file HRTF in ParamBin (to actiate when USE_NEW_HRTF_BINARY_FILE_FORMAT and FIX_777_COMBI_RENDER_CONFIG_FILE are on  )*/
 #define NON_BE_FIX_EVS_USAN_ERR_IN_WAVEADJUST           /* FhG: address issue 1037 */
 #define FIX_1038_OFFSET_TO_NULL_PTR_IN_EVS_TCX_BFI      /* FhG: move setting of pointers for parameter decoding so they are skipped in lost frames when they are not needed */
+#define NONBE_FIX_1056_ISM_RATE_SWITCH                  /* FhG: Fix #1056: fix TC buffer udpate on a ISM rate switch */	
 
 #define NONBE_FIX_984_OMASA_EXT_OUTPUT                  /* Nok: issue 1497 - porting OMASA EXT MR   */
 /* #################### End BASOP porting switches ############################ */
diff --git a/lib_dec/ivas_ism_dec.c b/lib_dec/ivas_ism_dec.c
index 330999862a548f4c076286c4b7febea5a7d38c5c..b3b19d4424334c4a63eed54531b80f66b294376e 100644
--- a/lib_dec/ivas_ism_dec.c
+++ b/lib_dec/ivas_ism_dec.c
@@ -125,8 +125,13 @@ static ivas_error ivas_ism_bitrate_switching_dec(
     }
 
     {
-        /* transfer subframe info from DirAC or ParamMC to central tc buffer */
+/* transfer subframe info from DirAC or ParamMC to central tc buffer */
+#ifdef NONBE_FIX_1056_ISM_RATE_SWITCH
+        /* only do this if we are not having done everything already in the TC decoding part and having only played out from the TC buffer */
+        if ( last_ism_mode == ISM_MODE_PARAM && st_ivas->hSpatParamRendCom != NULL && st_ivas->hTcBuffer->tc_buffer_mode != TC_BUFFER_MODE_BUFFER )
+#else
         if ( last_ism_mode == ISM_MODE_PARAM && st_ivas->hSpatParamRendCom != NULL && ( st_ivas->renderer_type != RENDERER_MONO_DOWNMIX && st_ivas->renderer_type != RENDERER_DISABLE ) )
+#endif
         {
             st_ivas->hTcBuffer->nb_subframes = st_ivas->hSpatParamRendCom->nb_subframes;
             st_ivas->hTcBuffer->subframes_rendered = st_ivas->hSpatParamRendCom->subframes_rendered;
diff --git a/lib_dec/ivas_jbm_dec.c b/lib_dec/ivas_jbm_dec.c
index 3371cc929850623137f1c2417ca655c4457300e1..ed9c49a51a35d1fe3ffcc0c47aefc40a18f910cf 100644
--- a/lib_dec/ivas_jbm_dec.c
+++ b/lib_dec/ivas_jbm_dec.c
@@ -2513,6 +2513,9 @@ static void ivas_jbm_dec_tc_buffer_playout(
         slots_to_render -= st_ivas->hTcBuffer->subframe_nbslots[last_sf];
         last_sf++;
     }
+#ifdef DEBUGGING
+    assert( slots_to_render == 0 );
+#endif
 
     for ( ch_idx = 0; ch_idx < st_ivas->hTcBuffer->nchan_transport_jbm; ch_idx++ )
     {