High deviation in transport channel 0 between float and fixed point decoder

Basic info

• Float reference:
  • Decoder (float):b09a7f47
• Fixed point:
  • Decoder (fixed):d5b43b02

Bug description

Core transport channel 0 output has high deviations between float and fixed point version starting at around 8.5 seconds (see screenshot, showing core transport channel 0 output before mixing matrix application for floating and fixed point). This issue is related to #929

Ways to reproduce

Encoder Command line -dtx -ism 3 bm6aa1s02.wav.0.csv bm6aa1s02.wav.1.csv bm6aa1s02.wav.2.csv -max_band FB 24400 48 bm6aa1s02.wav paramISM3--bm6aa1s02--24400--dtx.192

Decoder Command line EXT 48 paramISM3--bm6aa1s02--24400--dtx.192 paramISM3--bm6aa1s02--24400--dtx.clean.dec.flt.wav

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1232