Hey, thanks for replying!
I only have the PS5 version installed. It's definitely set to launch from that. I have ray tracing in the options menu too.
I wonder if the bugs are down to the content packs? Allow me to explain. On PS4 when Cold War was installed the content packs were shown as shared with Warzone. I copied over to my PS5 Warzone and separately installed Cold War PS5. I noticed the content packs on PS5 for cold war said shared with Warzone, below that was some more content packs that weren't shared. I had to reset my PS5 for another reason, did everything fresh for Warzone and Cold War and now don't have shared content packs. Maybe audio is glitching as a result? Or maybe that's relating to crashes people are having.
That step guide is missing "hit Game Version" by the way, some might get confused without that step as without pressing options, then Game Version, you won't see PS4 and PS5 options.