[mclehman]

That may be a Firefox on Windows issue (not that it helps you in this case). I regularly have ~1000 tabs open in Firefox on Linux with no issues (related to tabs and performance, anyway).

The only related issue for me recently was a failure to restore a session after Firefox forced a restart for an update. That's the behavior that chases me back to Brave on other systems (where it's not as easy to `tabs.sh > current_tabs` just in case).

[detaro]

Firefox on Windows handles hundreds of tabs also just fine in my experience (assuming you run some kind of ad/script-blocker, otherwise some runaway ad somewhere will probably get you). Only thing I can think of that something might have triggered the multi-process mode to disable - that'd cause performance problems, but can be forced through the settings.