The Extra Field entity type needs to be installed.

Problem/Motivation

Pending to D10 upgrade, I have the following error under Status Report. Site is on D9 and working, however, when certain content changes are made we do time and again get a database error, which goes away after a refresh.

Mismatched entity and/or field definitions
The following changes were detected in the entity type and field definitions.
Extra Field
The Extra Field entity type needs to be installed.

I acknowledge that this is likely a human error, but I have no clear way of troubleshooting this. The extension is installed and used by some content. What would be the best way to troubleshoot this? I am comfortable with database queries, and from what I can gather there is potentially database columns / schema differences, but not sure how to map what would be required to fix this (not knowing what schema is required)?