Issue with sound groups

I want to be able to muffle all sounds in my game using a sound group. Every sound in the game has the sound group. When the player takes explosion damage, he will enable the muffle on the client to simulate hearing loss etc.

The issue is that some sounds are not affected by the sound group, despite clearly having the sound group assigned. Something to note is that gun shots (coming from the tool in the character) are not muffled, while bullet impacts (coming from workspace) are muffled. Other sounds coming from character like walking sounds and such are also not muffled for some reason.

I believe the issue might be that sound groups dont affect sounds that are a descendant of character? However, so far I have not come to a conclusion or any fix. An idea I thought of was to move the gun shot sounds to the workspace at the same location as the player, then play the sound there, but at this point im contemplating to just abandon the muffle effect altogether.

The muffle effect is enabled by a client script (obviously cuz it has to play for that specific player).
As stated earlier, all sounds are assigned to that sound group.
No sounds are created during gameplay.

I would deeply appreciate if anyone has an explanation and solution to my issue. Thanks in advance.