I want to upgrade current kernel (linux-lts 5.10.85-1) to the newer stable (should be 5.15, I think), but kernel app from system settings doesn't display anything except the installed lts. In pamac I wasn't able to find vanila 5.15 too. Please advise what to do.
You might have to change the default kernel in Garuda Boot options, just try it and see if you need to.
You can check your currently running kernel with uname -a.