I self host vault warden, and the card auto-fill works ~70% of the time, and about half of those, the security code or the expiration doesn't work. EBay is the first one that comes to mind. I know it's the websites not following standards or conventions. It happens often enough that I remember the dates and codes now because I end up having to fill them in so often.

It seems really bad at filling CC info though. Like, I don't think it works at all. I always need to copy the number separately.

I still use it but it is annoying.