I don’t use a package manager to keep my custom packages updated, it is often causing more issues and troubles - just like this issue.
If you want to see which AUR scripts is different from your installed versions
- open Octopi
- click the Output tab in the lower pane
- Then click the Refresh button
Octopi is notoriously strange to work with when it comes to AUR - Pamac is somewhat better.
If you want a more reliable notification - consider reading Check if your AUR buildscript has changed