diff --git a/lib_com/fd_cng_com_fx.c b/lib_com/fd_cng_com_fx.c
index 0a1fe1d3287ee24cb325e1eae7a65acee2c82841..fc23ea45b5513295a240ce9bf87af3f1d4950dc8 100644
--- a/lib_com/fd_cng_com_fx.c
+++ b/lib_com/fd_cng_com_fx.c
@@ -166,7 +166,9 @@ void initFdCngCom(
 
     set16_fx( hFdCngCom->coherence_fx, 16384 /* 0.5 in Q15 */, MDCT_ST_DTX_NUM_COHERENCE_BANDS );
 
+#ifndef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
     set32_fx( hFdCngCom->olapBufferSynth_fx, 0, FFTLEN );
+#endif
     set32_fx( hFdCngCom->olapBufferSynth2_fx, 0, FFTLEN );
     set32_fx( hFdCngCom->exc_cng_32fx, 0, L_FRAME16k );
     set16_fx( hFdCngCom->exc_cng, 0, L_FRAME16k );
diff --git a/lib_com/options.h b/lib_com/options.h
index dd5034c929face931c707a25699bef0a9952a1e2..0feca9ea2db460ac7b1da407e9eeddff353972a1 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -99,6 +99,7 @@
 
 #define FIX_2448_RENDERER_MSAN_ERROR                    /* FhG: basop issue 2448: fix MSAN error with MSA rendering */
 #define FIX_2283_ISM_MD_DELAY                           /* Dolby: Fix ISM metadata delay round-off */
+#define FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING      /* FhG: basop issue 2262: correct buffer update for FD-CNG buffer in case of BR switching */
 
 /* ##################### End NON-BE switches ########################### */
 
diff --git a/lib_com/prot_fx.h b/lib_com/prot_fx.h
index f678394227320346ea2bcf74b2dc12bcb9fdde8f..f32d05534d06517f2b9e81dca1a40013fb058929 100644
--- a/lib_com/prot_fx.h
+++ b/lib_com/prot_fx.h
@@ -7214,7 +7214,9 @@ ivas_error core_switching_pre_dec_fx(
     const Word16 last_element_mode,   /* i  : last_element_mode            */
     const Word32 last_element_brate,  /* i  : last element bitrate         */
     const Word16 Q_old_synthFB,
+#ifndef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
     Word16 *Q_olapBufferSynth,
+#endif
     Word16 *Q_olapBufferSynth2 );
 
 ivas_error core_switching_post_dec_fx(
diff --git a/lib_com/stat_com.h b/lib_com/stat_com.h
index a85d6c7c013d62a4da41d8f93132dce64e52df2e..0ae17b976195e3dfec27be08c5e30a47dc9d8899 100644
--- a/lib_com/stat_com.h
+++ b/lib_com/stat_com.h
@@ -367,8 +367,10 @@ typedef struct
     Word16 fftlenFac;    // Q0
 
     Word16 timeDomainBuffer[L_FRAME16k]; /*Q15*/
-    Word32 olapBufferSynth_fx[FFTLEN];   /*Q_olapBufferSynth*/
-    Word32 olapBufferSynth2_fx[FFTLEN];  /*Q_olapBufferSynth2*/
+#ifndef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+    Word32 olapBufferSynth_fx[FFTLEN]; /*Q_olapBufferSynth*/
+#endif
+    Word32 olapBufferSynth2_fx[FFTLEN]; /*Q_olapBufferSynth2*/
 
     const Word32 *olapWinAna_fx; /* Q30 */
     const Word16 *olapWinSyn_fx; /* Q15 */
diff --git a/lib_dec/amr_wb_dec_fx.c b/lib_dec/amr_wb_dec_fx.c
index 5eef39ba7f50e78f89b6f447f4fc34632ecf4b4c..b8515e399a7295b860f692c97c728634fb763c35 100644
--- a/lib_dec/amr_wb_dec_fx.c
+++ b/lib_dec/amr_wb_dec_fx.c
@@ -173,7 +173,11 @@ ivas_error amr_wb_dec_fx(
     }
 
     /* Updates in case of EVS -> AMR-WB IO switching */
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+    IF( NE_32( ( error = core_switching_pre_dec_fx( st_fx, output_frame, -1, 1, EVS_MONO, EVS_MONO, -1, &tmp16 ) ), IVAS_ERR_OK ) )
+#else
     IF( NE_32( ( error = core_switching_pre_dec_fx( st_fx, output_frame, -1, 1, EVS_MONO, EVS_MONO, -1, &tmp16, &tmp16 ) ), IVAS_ERR_OK ) )
+#endif
     {
         return error;
     }
diff --git a/lib_dec/core_switching_dec_fx.c b/lib_dec/core_switching_dec_fx.c
index b8f4cc63f126f5fbef8fc1dd48013db3d982e251..2eab8f473a48006755fe8567e3b7485fb0497e7c 100644
--- a/lib_dec/core_switching_dec_fx.c
+++ b/lib_dec/core_switching_dec_fx.c
@@ -1158,7 +1158,9 @@ ivas_error core_switching_pre_dec_fx(
     const Word16 last_element_mode,   /* i  : last_element_mode            */
     const Word32 last_element_brate,  /* i  : last element bitrate         */
     const Word16 Q_old_synthFB,
+#ifndef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
     Word16 *Q_olapBufferSynth,
+#endif
     Word16 *Q_olapBufferSynth2 )
 {
     Word32 tmp_fx; /*Q-12*/
@@ -1952,23 +1954,40 @@ ivas_error core_switching_pre_dec_fx(
                 test();
                 IF( LE_32( st->total_brate, SID_2k40 ) && LE_32( st->last_total_brate, SID_2k40 ) )
                 {
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+                    lerp( st->hFdCngDec->hFdCngCom->olapBufferSynth, st->hFdCngDec->hFdCngCom->olapBufferSynth, shl( st->L_frame, 1 ), shl( st->last_L_frame, 1 ) );
+#else
                     L_lerp_fx( st->hFdCngDec->hFdCngCom->olapBufferSynth_fx, st->hFdCngDec->hFdCngCom->olapBufferSynth_fx, shl( st->L_frame, 1 ), shl( st->last_L_frame, 1 ), Q_olapBufferSynth );
+#endif
 
                     IF( EQ_16( st->L_frame, L_FRAME ) )
                     {
                         FOR( i = 0; i < shl( st->L_frame, 1 ); i++ )
                         {
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+                            st->hFdCngDec->hFdCngCom->olapBufferSynth[i] = mult_r( st->hFdCngDec->hFdCngCom->olapBufferSynth[i], 20480 /* Q15*/ ); /* (Q15 - olapBufferSynth_exp) */
+                            move16();
+#else
                             st->hFdCngDec->hFdCngCom->olapBufferSynth_fx[i] = Mult_32_16( st->hFdCngDec->hFdCngCom->olapBufferSynth_fx[i], (Word16) 20480 /* 0.6250f in Q15 */ );
                             move32();
+#endif
                         }
                     }
                     ELSE
                     {
                         FOR( i = 0; i < shl( st->L_frame, 1 ); i++ )
                         {
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+                            st->hFdCngDec->hFdCngCom->olapBufferSynth[i] = mult_r( st->hFdCngDec->hFdCngCom->olapBufferSynth[i], 26214 /* Q14*/ ); /* (Q15 - olapBufferSynth_exp) + 1 */
+                            move16();
+#else
                             st->hFdCngDec->hFdCngCom->olapBufferSynth_fx[i] = Mult_32_16( L_shl( st->hFdCngDec->hFdCngCom->olapBufferSynth_fx[i], 1 ), (Word16) 26214 /* 1.6f in Q14 */ );
                             move32();
+#endif
                         }
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+                        st->hFdCngDec->hFdCngCom->olapBufferSynth_exp = add( st->hFdCngDec->hFdCngCom->olapBufferSynth_exp, 1 );
+#endif
                     }
                 }
             }
diff --git a/lib_dec/evs_dec_fx.c b/lib_dec/evs_dec_fx.c
index e9673e0caf79d40d1b80babad186e3c2874ae703..016a41a0411a3be0f5aaa777dd003263da9637b2 100644
--- a/lib_dec/evs_dec_fx.c
+++ b/lib_dec/evs_dec_fx.c
@@ -315,8 +315,11 @@ ivas_error evs_dec_fx(
         /*---------------------------------------------------------------------*
          * Preprocessing (preparing) for ACELP/HQ core switching
          *---------------------------------------------------------------------*/
-
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+        IF( ( error = core_switching_pre_dec_fx( st_fx, output_frame, -1, 1, EVS_MONO, EVS_MONO, -1, &tmp16 ) ) != IVAS_ERR_OK )
+#else
         IF( ( error = core_switching_pre_dec_fx( st_fx, output_frame, -1, 1, EVS_MONO, EVS_MONO, -1, &tmp16, &tmp16 ) ) != IVAS_ERR_OK )
+#endif
         {
             return error;
         }
diff --git a/lib_dec/ivas_core_dec_fx.c b/lib_dec/ivas_core_dec_fx.c
index 425ceb05b1e3e5a38eebaa06e447c70dcfe4e2f1..a90da1f416e9a433a75dbcad536b23bd4b469f54 100644
--- a/lib_dec/ivas_core_dec_fx.c
+++ b/lib_dec/ivas_core_dec_fx.c
@@ -438,7 +438,13 @@ ivas_error ivas_core_dec_fx(
         /*---------------------------------------------------------------------*
          * Preprocessing (preparing) for ACELP/HQ core switching
          *---------------------------------------------------------------------*/
+#ifdef FIX_BASOP_2262_OLAP_BUFFER_SYNTH_SWITCHING
+        Word16 Q_olapBufferSynth2;
+        Q_olapBufferSynth2 = Q15; /*Initializing with max values to avoid warnings*/
+        move16();
 
+        IF( NE_32( ( error = core_switching_pre_dec_fx( st, output_frame, sts[0]->last_core_brate, nchan_out, last_element_mode, last_element_brate, st->Q_syn, &Q_olapBufferSynth2 ) ), IVAS_ERR_OK ) )
+#else
         Word16 Q_olapBufferSynth, Q_olapBufferSynth2;
 
         Q_olapBufferSynth = Q15;  /*Initializing with max values to avoid warnings*/
@@ -447,6 +453,7 @@ ivas_error ivas_core_dec_fx(
         move16();
 
         IF( NE_32( ( error = core_switching_pre_dec_fx( st, output_frame, sts[0]->last_core_brate, nchan_out, last_element_mode, last_element_brate, st->Q_syn, &Q_olapBufferSynth, &Q_olapBufferSynth2 ) ), IVAS_ERR_OK ) )
+#endif
         {
             return error;
         }