Severe Performance Drop and Audio/Visual Issues in Apex

Hi everyone. I've been playing Apex for years on a mid-range PC I built around 2020, and I’ve never had major issues. However, over the past year, I’ve noticed a significant performance downgrade and increasingly frequent crashes during the first match played, which then don’t happen again for the rest of the session.
I can't figure out which component is causing the game to no longer run as smoothly as it used to.

The most noticeable problems are:

black or frozen screen at the start,

longer loading times for character skins when entering the lobby,

and most importantly, audio issues — for example, gunfire sounds are delayed compared to the visuals, which makes it impossible to react properly to enemy attacks.

Can anyone help me out?