Regarding your specific CPU (and iGPU), kernel 5.4 should be fine, though you did say:
You can either go back to that kernel, and ask for help fixing the issue on this forum. Or go to Kernel 5.10 and ask for help fixing that issue. Or just try kernel 5.11, which might fix your issue on it’s own.
If you noticed your FPS is lower in games for example. Or maybe compiling packages is slower on one kernel versus another. Or read articles.
For example, kernel 5.11 had some regressions specifically on AMD computers, which is why I didn’t swap. But now that it’s fixed, I’ll probably swap to it.
I am always on /r/linux_gaming, because plenty of people talk about regression and progression of kernels for some hardware.