Hmm. My situation might have a weird circumstance as well: I installed a new version of manjaro, which ships a profile by default with manjaro homepage etc. bookmarked. I signed into sync; normal one pulled down. The manjaro one is what got mysteriously applied. Old profile gone. I can only imagine what would be causing it; don't remember changing anything whatsoever. Did you by any chance sign in on a new computer before it happened? My windows was the one that went wonky; linux was the newly signed in. Glad to hear it's not just me, though. I was to the point of thinking a rabid script went crazy and deleted my profile.