Are you using it in clamshell mode? Where you keep the lid closed and use an external monitor, keyboard, and mouse (you mentioned mbp and macbook air in your post). If so, I have heard about multiple problems like sleep/wake and cooling issues across multiple models and multiple OS releases. That is a specific use case I've heard avid mac users complain about over the years.
I did encounter corrupted Time Machine backups when I set up my own network Time Machine Server in Linux (using netatalk). When my laptop would go to sleep in the middle of a backup over wifi the whole backup would get corrupted. I haven't had that problem since I switched to using Synology as a network Time Machine server (I never had it happen when using a USB Time Machine backup, either). I've never used a Time Capsule.
I did encounter corrupted Time Machine backups when I set up my own network Time Machine Server in Linux (using netatalk). When my laptop would go to sleep in the middle of a backup over wifi the whole backup would get corrupted. I haven't had that problem since I switched to using Synology as a network Time Machine server (I never had it happen when using a USB Time Machine backup, either). I've never used a Time Capsule.