I didnt manage to fix it.
What I did was to create a new field called Change Summary (possible as the main content even), and each time I changed anything I updated it. This forced a new revision to be stored.
Thanks for an amazing plugin guys.
I have a similar issue.
When I make an edit to the custom fields themselves without editing the title or content, then yes the revision will be saved.
However the revision is not shown in the compare section below. It will only show me the differences between the previous revisions and the current if I edit the title or content.
Is it possible to fix this bug please?