Nevermind ... after this was bugging me for weeks I finally had a moment of realisation right after posting this that it was a BIOS setting called "power saver" that needed be disabled.
Whenever I am on battery power, the screen brightness immediately drops to zero as soon as the battery reaches 30%. I can set the brightness back to 100%, plug it in for a second, and unplug again, and it will immediately drop back to 0% brightness.
Power saver is not enabled
No third party...
Whenever I connect my desk monitor to my laptop (or disconnect it), and sometimes even randomly for no reason, the Start button will stop working - i.e. I click it but the start menu does not appear. The solution is to either restart Explorer, or as I realised a little less annoying than that...
Quick update: I created a fresh user account, and the icons work fine on that, so it's not related to the Windows 11 installation but rather the user account. Maybe this information can help.
Thanks for your reply. I posted the thread on Reddit as well (link), looks like there are at least two others who had this issue, one of them who did an update from a clean install of Win 10 to Win 11, so seems like the issue happens even if you don't have a heavily tweaked Win 10 installation...
I upgraded from Win 10 21H1 to Win 11 last night, everything working fine except the battery and edit icons are missing from the bottom of the quick actions flyout, only the settings button is visible:
I had a number of tweaks via Winaero, Group Policy, etc on my Win 10 installation but I...