Pi 5B 64-bit OS Major Problems

Hi - I have just got a Pi 5B and installed the 64-bit OS. When I try to run Processing everything goes haywire - crashes, etc… It all ran fine on my Pi 4B. I suspect the OS is buggy - you can’t remove the taskbar for eg. Anyone got any ideas what to do? I’ll head back to my 4B for the time being but some of my apps need a bit more power and I was hoping the 5B would solve the problem.

Thanks in advance.
Paul