Lock switch button not operating

Got the same problem on the OnePlus Nord 2 5G.
In My Opinion, it's a software issue and not Hardware. The Problem started straight after the software update to android 13 and the button works sometimes many times in a row without any problems. Sometimes, the 3rd, 5th or 15th click is registered (same position on the button, same pushing force...).

There is a workaround for automated shutdown/startups by scheduling a time. in case the shutdown really doesn't work, use this and set it to 1 minute in the future - and if you want to restart, set a turn-on time as well!
I had the problem that I couldn't turn it back on via buttonpress anymore and had to connect a charger to get the phone to boot once.