Which kernel upgrade? I have a dell precision with 12th Generation Intel i5-12500H, and it can't suspend properly. The suspend is even flaky and fails to suspend at all half the time. I run fedora with a very new kernel. It has a Nvidia GPU though. But then again - it is "Ubuntu certified"...
Drain on suspend in particular has largely been resolved on newer mainboards, firmware, and kernel updates, though I don't have an 11th-gen Intel and haven't run Ubuntu for a long time.
Kernel updates fixed this on my 12th-gen, firmware updates fixed it on my 7040, and my Ultra 7 155H never experienced this issue.