Low-frequency "thump" in MASA format using bitrate switching and output to MONO

Basic info

• Encoder (float): d18cbee3
• Decoder: 10b97f38

Bug description

There is an audible "thump" in latter part of short MASA test vector stv2MASA2TC48c when using attached rate switching profile and rendering to MONO output. Here is a diff plot between BASOP and ivas-float-update:

Ways to reproduce

Use the switching profile generic_start_13k2_20frames.bin

with commands

./IVAS_cod -q -masa 2 scripts/testv/stv2MASA2TC48c.met -max_band fb generic_start_13k2_20frames.bin 48 scripts/testv/stv2MASA2TC48c.wav test.bs
./IVAS_dec -q MONO 48 test.bs out.wav