Pages assigned via settings disappeared (not in trash)

Hi everyone,

I’m seeing a very strange issue and hope you can provide insight. Pages that are assigned in settings – like home, shop, terms, etc. – disappear. As in, they’re not in the Pages list, and also not in trash. I’ve been troubleshooting sites for many years but never seen anything like this. The site owner restores a backup when this happens. It’s happened a couple of times in the past few weeks.

Thank you.