Few keyboard keys stopped functioning after recent macOS update on MacBook.

My guess is the KB itself, or battery swelling perhaps, try a cheap wired USB KB to test.

I have been having the same issue with the Q, A, and Z keys. The keys around them, like Caps Lock and the brightness low key, also don't work. The issue has persisted for the last five months. However, it starts working fine intermittently for a week or two, as if nothing had ever happened to the keyboard. 

I wonder if this is a widespread issue, as I have seen many similar keyboard issues being reported with no resolution coming from Apple. 

I'm guessing swelling battery or heat.

Yes, this is MacBook Pro M1 2021 14" laptop.

There has been a patter to the problem. Initially, the only time the keys behaved abruptly was when the laptop was switched on. After about half hour of malfunctioning, the keys work fine for the entire day till the next rebooting. This was about 8 months back. After about 2 months, it stopped working normally for 5 months till now with only an exception of last week where the keys worked flawlessly for a week. Now, it is back to the same abrupt behaviour wherein I have to press 'a', 'q' and 'z' multiple times to make them work.

Is this a Laptop?