A family of Microsoft relational database management systems designed for ease of use.
It must've been a corrupted form. After checking several more backups I found one that displayed the number of records.
Having many backups helped.
If a form has become corrupted, in my experience a quick and simple way to fix it in most cases is to select the form in the navigation pane and copy it to the clipboard. Then paste it back under a new name. If the copy works correctly you can then delete the original and rename the copy back to the original name.