Can't win a fight anymore...

I'm looking for some help with hopefully just system settings on the PS5.  I don't play cross-play, just console only.

Since the last patch I've had some horrible lag, packet loss, etc.  I can no longer win a gun fight fight even if I get the jump someone.  Pretty much, if I start shooting and don't kill hem before they see me, I am dead.  I've had numerous instances where I've met someone around a corner and I'm dead before I can even pull the trigger, and not to a head shot but a good 4 shots within 1/10th of a second.  

At first I thought I would try different weapons, high damage, high RPM, etc. no help I lose 90% of fights I initiate.  I die to gunfights with teammates in a direct line between me and the enemy yet somehow my teammate walks away. I die to grenades 20 feet away but somehow my grenades that land on people do nothing.  

I have to assume at this point what I am seeing on my screen is a good second behind everyone else around me.  There are way too many WTF moments (corroborated by my family watching and asking me how I died on way too many occasions).

Are there any additional settings I should try on the PS5 that might help?  I am on WIFI about 20 feet away from my modem but it has to go through 2 walls.  I get very low pings with no packet loss in the room and my speeds are around 100/20 according to Speedtest.  I can't hardwire it as I'd have to run the line all the around the house.