diff --git a/lib_dec/core_dec_init_fx.c b/lib_dec/core_dec_init_fx.c
index 51416a0aebd278b6f9166185dfd05c59b3f085b1..a3c76e23cb99e7a3aa4dbc1ba191eaa0e25f0ed3 100644
--- a/lib_dec/core_dec_init_fx.c
+++ b/lib_dec/core_dec_init_fx.c
@@ -490,11 +490,15 @@ void open_decoder_LPD_fx(
                 lerp( hHQ_core->old_out_fx, hHQ_core->old_out_LB_fx, st->L_frame, hTcxDec->L_frameTCX );
 
                 Copy( hHQ_core->old_out_fx + nz, hTcxDec->syn_Overl_TDACFB, shr( hTcxDec->L_frameTCX, 1 ) ); /* exp(exp_old_out) */
+                hTcxDec->Q_syn_Overl_TDACFB = hHQ_core->Q_old_wtda;
+                move16();
                 nz = NS2SA_FX2( st->sr_core, N_ZERO_MDCT_NS );
                 move16();
                 Copy( hHQ_core->old_out_LB_fx + nz, hTcxDec->syn_Overl_TDAC, shr( st->L_frame, 1 ) ); /* hHQ_core->q_old_outLB_fx */
                 hHQ_core->Q_old_wtda_LB = hHQ_core->Q_old_wtda;
                 move16();
+                hTcxDec->Q_syn_Overl_TDAC = hHQ_core->Q_old_wtda_LB;
+                move16();
             }
 #else
             PMT( "acelp_plc_mdct_transition is missing" )
@@ -1210,11 +1214,15 @@ void acelp_plc_mdct_transition_fx(
 
         lerp( st->hHQ_core->old_out_fx, st->hHQ_core->old_out_LB_fx, st->L_frame, st->hTcxDec->L_frameTCX );
         Copy( st->hHQ_core->old_out_fx + nz, st->hTcxDec->syn_Overl_TDACFB, shr( st->hTcxDec->L_frameTCX, 1 ) ); /* exp_old_out */
+        st->hTcxDec->Q_syn_Overl_TDACFB = st->hHQ_core->Q_old_wtda;
+        move16();
 
         nz = NS2SA_FX2( st->sr_core, N_ZERO_MDCT_NS );
         Copy( st->hHQ_core->old_out_LB_fx + nz, st->hTcxDec->syn_Overl_TDAC, shr( st->L_frame, 1 ) ); /* exp_old_out */
         st->hHQ_core->Q_old_wtda_LB = st->hHQ_core->Q_old_wtda;
         move16();
+        st->hTcxDec->Q_syn_Overl_TDAC = st->hHQ_core->Q_old_wtda_LB;
+        move16();
     }
 
     return;
diff --git a/lib_dec/dec_tcx_fx.c b/lib_dec/dec_tcx_fx.c
index 1f0bb5d6a407cb16de77f8d1006ad1c4af7e05f4..53b688e729bb6cc428774e3d09afbd9b507846ad 100644
--- a/lib_dec/dec_tcx_fx.c
+++ b/lib_dec/dec_tcx_fx.c
@@ -3842,8 +3842,12 @@ void decoder_tcx_ivas_fx(
     }
 
     /* Scaling down buffers for decoder_tcx_imdct_fx*/
-    Scale_sig( st->hTcxDec->syn_Overl_TDACFB, L_FRAME_MAX / 2, 1 );                              // Scaling to Q_syn
-    Scale_sig( st->hTcxDec->syn_Overl_TDAC, L_FRAME32k / 2, 1 );                                 // Scaling to Q_syn
+    Scale_sig( st->hTcxDec->syn_Overl_TDACFB, L_FRAME_MAX / 2, sub( st->Q_syn, st->hTcxDec->Q_syn_Overl_TDACFB ) ); // Scaling to Q_syn
+    st->hTcxDec->Q_syn_Overl_TDACFB = st->Q_syn;
+    move16();
+    Scale_sig( st->hTcxDec->syn_Overl_TDAC, L_FRAME32k / 2, sub( st->Q_syn, st->hTcxDec->Q_syn_Overl_TDAC ) ); // Scaling to Q_syn
+    st->hTcxDec->Q_syn_Overl_TDAC = st->Q_syn;
+    move16();
     Scale_sig( st->hHQ_core->old_out_fx, L_FRAME48k, negate( st->hHQ_core->Q_old_wtda ) );       // Scaling to Q_syn
     Scale_sig( st->hHQ_core->old_out_LB_fx, L_FRAME32k, negate( st->hHQ_core->Q_old_wtda_LB ) ); // Scaling to Q_syn
     st->hHQ_core->Q_old_wtda = 0;
diff --git a/lib_dec/er_dec_acelp_fx.c b/lib_dec/er_dec_acelp_fx.c
index defb1970a186ce0d5449a89edbbfb15862f861c2..b093fb12928bbe13a084ccc65b3457cb996ab600 100644
--- a/lib_dec/er_dec_acelp_fx.c
+++ b/lib_dec/er_dec_acelp_fx.c
@@ -1101,6 +1101,8 @@ void con_acelp_fx(
 
     /* save last half frame if next frame is TCX */
     bufferCopyFx( syn + st->L_frame, hTcxDec->syn_Overl_TDAC, shr( st->L_frame, 1 ), 0 /*Qf_syn*/, -1 /*Qf_old_xnq*/, 0, 0 /*Q_old_xnq*/ );
+    hTcxDec->Q_syn_Overl_TDAC = add( st->Q_syn, -1 );
+    move16();
     Copy( syn + sub( st->L_frame, M + 1 ), st->syn, 1 + M );
 
     /* update old_Aq */
@@ -1179,6 +1181,8 @@ void con_acelp_fx(
 
     /* update memory for full band */
     lerp( hTcxDec->syn_Overl_TDAC, hTcxDec->syn_Overl_TDACFB, shr( hTcxDec->L_frameTCX, 1 ), shr( st->L_frame, 1 ) );
+    st->hTcxDec->Q_syn_Overl_TDACFB = st->hTcxDec->Q_syn_Overl_TDAC;
+    move16();
     lerp( hTcxDec->syn_Overl, hTcxDec->syn_OverlFB, shr( hTcxDec->L_frameTCX, 1 ), shr( st->L_frame, 1 ) );
     lerp( hHQ_core->old_out_LB_fx, hHQ_core->old_out_fx, hTcxDec->L_frameTCX, st->L_frame );
 
diff --git a/lib_dec/er_dec_tcx_fx.c b/lib_dec/er_dec_tcx_fx.c
index 48299ed3289fc09f5013754dad211dea6dfc6b45..4158368c6d9d7952165b8915b35563c68a86b72f 100644
--- a/lib_dec/er_dec_tcx_fx.c
+++ b/lib_dec/er_dec_tcx_fx.c
@@ -1092,6 +1092,8 @@ void con_tcx_fx(
 
     /* create aliasing and windowing need for transition to TCX10/5 */
     bufferCopyFx( syn + L_frame, hTcxDec->syn_Overl_TDACFB, shr( L_frame, 1 ), Q_syn, 0, -1, 0 );
+    hTcxDec->Q_syn_Overl_TDACFB = add( st->Q_syn, sub( st->Q_syn, -1 ) );
+    move16();
 
     FOR( i = 0; i < W12; i++ )
     {
@@ -1146,6 +1148,8 @@ void con_tcx_fx(
     Scale_sig( hTcxDec->old_syn_Overl, shr( st->L_frame, 1 ), sub( -1, Q_syn ) );
     lerp( hTcxDec->syn_OverlFB, hTcxDec->syn_Overl, shr( st->L_frame, 1 ), shr( L_frame, 1 ) );
     lerp( hTcxDec->syn_Overl_TDACFB, hTcxDec->syn_Overl_TDAC, shr( st->L_frame, 1 ), shr( L_frame, 1 ) );
+    hTcxDec->Q_syn_Overl_TDAC = hTcxDec->Q_syn_Overl_TDACFB;
+    move16();
     lerp( st->hHQ_core->old_out_fx, st->hHQ_core->old_out_LB_fx, st->L_frame, L_frame );
 
     st->old_enr_LP = Enr_1_Az_fx( A_local, L_SUBFR ); /*Q3*/
@@ -2100,6 +2104,8 @@ void con_tcx_ivas_fx(
 
     /* create aliasing and windowing need for transition to TCX10/5 */
     bufferCopyFx( syn + L_frame, hTcxDec->syn_Overl_TDACFB, shr( L_frame, 1 ), Q_syn, 0, -1, 0 );
+    hTcxDec->Q_syn_Overl_TDACFB = add( Q_syn, sub( Q_syn, -1 ) );
+    move16();
 
     FOR( i = 0; i < W12; i++ )
     {
@@ -2148,6 +2154,8 @@ void con_tcx_ivas_fx(
     Scale_sig( hTcxDec->old_syn_Overl, shr( st->L_frame, 1 ), sub( -1, Q_syn ) );
     lerp( hTcxDec->syn_OverlFB, hTcxDec->syn_Overl, shr( st->L_frame, 1 ), shr( L_frame, 1 ) );
     lerp( hTcxDec->syn_Overl_TDACFB, hTcxDec->syn_Overl_TDAC, shr( st->L_frame, 1 ), shr( L_frame, 1 ) );
+    hTcxDec->Q_syn_Overl_TDAC = hTcxDec->Q_syn_Overl_TDACFB;
+    move16();
     lerp( st->hHQ_core->old_out_fx, st->hHQ_core->old_out_LB_fx, st->L_frame, L_frame );
 
     st->old_enr_LP = Enr_1_Az_fx( A_local, L_SUBFR ); /*Q3*/
diff --git a/lib_dec/ivas_mdct_core_dec.c b/lib_dec/ivas_mdct_core_dec.c
index 608fc99874c0536c4f0c58b010d5f99ceebfc399..777d18f5c1fb0bfbd26dca003c03b5df1256939f 100644
--- a/lib_dec/ivas_mdct_core_dec.c
+++ b/lib_dec/ivas_mdct_core_dec.c
@@ -2052,8 +2052,8 @@ void ivas_mdct_core_reconstruct_fx(
         set16_fx( synthFB_fx, 0, L_FRAME_PLUS + M );
         IF( st->core != ACELP_CORE )
         {
-            Scale_sig( st->hTcxDec->syn_Overl_TDACFB, L_FRAME_MAX / 2, sub( q_win, sub( -1, st->Q_syn ) ) );
-            Scale_sig( st->hTcxDec->syn_Overl_TDAC, L_FRAME32k / 2, sub( q_win, sub( -1, st->Q_syn ) ) );
+            Scale_sig( st->hTcxDec->syn_Overl_TDACFB, L_FRAME_MAX / 2, sub( q_win, st->hTcxDec->Q_syn_Overl_TDACFB ) );
+            Scale_sig( st->hTcxDec->syn_Overl_TDAC, L_FRAME32k / 2, sub( q_win, st->hTcxDec->Q_syn_Overl_TDAC ) );
             Scale_sig( st->hTcxDec->old_syn_Overl, L_FRAME32k / 2, sub( q_win, sub( -1, st->Q_syn ) ) );
             Scale_sig( st->hTcxDec->syn_Overl, L_FRAME32k / 2, sub( q_win, st->Q_syn ) );
             Scale_sig( st->hTcxDec->syn_OverlFB, L_FRAME_MAX / 2, sub( q_win, st->Q_syn ) );
@@ -2116,7 +2116,11 @@ void ivas_mdct_core_reconstruct_fx(
                 st->Q_syn = add( q_win, sf );
             }
             Scale_sig( st->hTcxDec->syn_Overl_TDACFB, L_FRAME_MAX / 2, sub( sub( -1, st->Q_syn ), q_win ) );
+            st->hTcxDec->Q_syn_Overl_TDACFB = sub( -1, st->Q_syn );
+            move16();
             Scale_sig( st->hTcxDec->syn_Overl_TDAC, L_FRAME32k / 2, sub( sub( -1, st->Q_syn ), q_win ) );
+            st->hTcxDec->Q_syn_Overl_TDAC = sub( -1, st->Q_syn );
+            move16();
             Scale_sig( st->hTcxDec->old_syn_Overl, L_FRAME32k / 2, sub( sub( -1, st->Q_syn ), q_win ) );
 #ifdef MSAN_FIX
             Scale_sig( synth_buf_fx, add( add( st->hTcxDec->old_synth_len, L_FRAME_PLUS ), M ), sub( q_syn, q_win ) );