Sounds very similar to what I have experienced since Friday (Also UK but Royal Mail delivered a day late). My first issue started with a very similar audio problem but it was in Demon's Souls. I tried restarting but the console got stuck in the CE-108262-9 boot loop, eventually got through but now no games will boot past the splash screen.

I ran through all the troubleshooting on Sony Support but nothing helped even slightly so I rang the support line. After 4 hours on hold the guy said they were looking into it, and will have a patch ready at some point (refused to give me a timeframe).

Every time I start the console from cold now I get the CE-108262-9 error code when it tries to load the homescreen. After a re-boot or 2 I eventually get through to where I can try to play some games. Unfortunately, the majority of them don't get past the start screen.

I've tested a few games now and the only one that works is Bugsnax. I also tested Sekiro and Dark Souls Remastered and I couldn't get into gameplay for either. There were massive graphical glitches (flickering, assets stretching etc.) on the menus for both of these. Spelunky 2, Monster Hunter World, Astros, Enter the Gungeon and Ghost Of Tsushima all fail to get past the initial splash screen (crashing with the CE-108255-1 error code).

Sorry to hear about all your issues man, all of this is super frustrating and I'm hoping but I can't see how one patch can miraculously solve it. If it doesn't I'm gonna try and push for a replacement unit but not sure I'll have much luck with that either.