After my mac restarted, all my tabs are in a group that I can't ungroup. All my preexisting groups are gone

After my macbook pro (Sequoia 15.7.7) restarted, every tab in both of my open Firefox windows were moved to a *tab group in a single window.* The tab group's name is the date—e.g., "2026-10-11 10:50 *". Right-click + `ungroup tabs` does nothing. If I open a new window, it automatically has a tab open in a tab group with a similar name. I can't move tabs into new tab groups. I hate this. I've lost all my previous tab groups, which I use to organize my work and hobbies, and now that's all gone. I've experienced this on TWO macbook pros. I also have a Windows 10 desktop, but that continues to work as expected.

Months ago, I disabled all AI features, and, and so in `about:config`, I can observe that `browser.tabs.groups.smart.*` are all set to false. I also just tried setting `browser.tabs.groups.enabled` to false, but it had no effect.