I have MBA M1 and I noticed that the delete key now lags with a single press with the Mac OS 12.1. It doesn't lag when I double or triple press on it. It's more noticeable on the URL bar web browsers. Is there a way to fix the delete key lag?
So you're saying when you press the delete key once, there's a noticable delay between when you press the key and when you see the character on the screen disappear? If so, I have not experienced that outside an entire app being laggy (and in that case it's any keys, not just the delete key). Not even when using a Bluetooth keyboard has that happened for me on my M1 MBA. I'm assuming you've already tried quitting/restarting the apps and also rebooting the computer?
Just to say I have the exact same problem, on the exact same model. The latency is very noticeable on Safari when I try to delete some characters on the address bar, just as you.