I've used the cheapo Wyze Lock (https://www.wyze.com/products/wyze-lock?variant=423027510806...), which is a deadbolt-only replacement with the $20 keypad (https://www.wyze.com/products/wyze-lock-keypad?srsltid=AfmBO...) and it's worked well for a few years. The buttons never gave me any issues, and indeed I use that instead of the app to unlock.

After a few years and several doors/apts, the deadbolt itself seems to be showing some issues sometimes (have to pull the door close tightly for it to lock right)... I'm not sure if that's a door alignment issue or maybe a thermal freeze/thaw issue or something... need to debug it further... but it's a lot cheaper and more reliable (and uglier) than most smart locks I've tried, including the much fancier ones.