Hijack away!
No, I don't use btrfs, I've only got ext4 in place.
I've gone back to 5.11.20-1 and everything is working fine on my Quad Core Intel Core i7-6700. I don't think I've anything unusual on my set up other than using 4k output on my NVIDIA GK104 [GeForce GTX 770]. Since dibl isn't having issues, it seems there isn't a general fault and I'll have to uncover my issues on the machine that is experiencing them. One of my machines. After dibl's news, I installed on a couple of laptops and they don't seem to be having issues.