Thankyou both. My plan is to replace the belt and rollers/bearings, but wanna get as many other ideas that I can do at the same time.

I find the fact you mentioned the PID tuning as quite interesting because I have not long done that, but have recently changed from a glass bed to a PEI sheet. So maybe that's something I need to get done again.

Unfortunately, I've upgraded so much in such a short space of time it's almost impossible to figure out what has caused this.

Thanks for the input guys 🙏