huh. Just had to close and re-open one of the windows too; tabs that were already loaded were just rendering as white, with a little black dot in the upper left corner (which maybe was the entire contents of the page all going to 0,0? idk)
This might be Firefox's death rattle for me. sigh.
@ChateauErin Hmm, YouTube does this (or something similar) to me from time to time, but only with specific videos. If I load that URL in a new window, I just see an empty white page, but if I load it in a private window, everything displays correctly. I assumed it was Google doing gross A/B testing in production