Yes it only happened with TotalFinder.app. You can’t assign an application to “open with” another application via Contextual menu nor Get Info. It wasn’t that. I forgot there was also an AppleScript warning from TotalFinder via Notifications, that when clicked on sent me to the pinned forum post: TotalFinder does not launch
I just did a total uninstall of TotalFinder 1.6.20, plus searched for and removed all caches, plists, etc associated with it. I then reinstalled & updated to 1.6.20 & it’s working fine.
Don’t know what happened between the last update & this new update. But a clean install fixed the issue.
Thanks anyway.