@docarzt – genius!
Took two tries, but it took the second time. I don’t understand what was causing a ‘delay’ in it.
When I disabled the plugin, all my posts were still broken, and then seemed to right themselves a minute or two later.
Then after commenting out that dumb flush_rules() line, I reactivated the plugin… and it was broke again. So I deactivated (again), waited a minute (again), then reactivated (again).
Everything is back to normal now. Anyone know why WP wasnt keeping up? (cache was disabled the whole time)