Hey Gazumped,
Your poking may have helped, we recently had someone from Evernote reach out and provide a temporary fix.
The temporary fix was Evernote manually triggering a reindexing for our business. After the reindexing, we were near-immediately able to search for all previously unsearchable old notes, no update or reinstall necessary. So unfortunately, if this affects us again or any other Evernote customer, it seems like it requires a manual fix from Evernote Support.
Evernote Support said their developers will investigate the underlying bug and that they're available to trigger the reindexing again if it occurs before the bug is fixed. It's still just very odd to me I can't seem to find any record of this bug ever affecting anyone else, yet this is the second time it's happened to our organization on the most expensive Evernote plan (Teams, as opposed to Personal or Professional).
Just documenting all this in the forums in the off-chance it ever helps someone else in the future. Thank you for your kind assistance!
