You're talking about a different problem. How can you explain this same issue on two brand new MacBook Pro 16-inchs bought two years apart? There's no way I'm pouring glue into my speakers.

Same here, I had a 2019 MBP 16" and now have a 2021 MBP 16", both had this problem. It's one of the reasons I upgraded and it seems it wasn't fixed!

I think you might be right on the memory pressure thing. (Although I always thought that MacOS tried to load as much into memory as possible). I also wish I'd gone for the 32GB now, but regardless, a nearly £3000 computer should not have this problem. What's it going to take for Apple to even acknowledge that it's still an issue?