Uninstall doesn't remove custom field groups, but the field group is not visible in custom fields

When uninstalling the latest version of the extension, the Areas custom field group for contacts is not removed, but it no longer appears in custom fields either. It can be disabled or deleted via API, but not from the UI. The results is this on all contacts:

I verified this on dmaster. There was an error shown on dmaster when installing the extension that might be related:

This appears the be same as this past issue.