UPDATE:
I've tried selectively enabling and disabling Safari extensions and it seems to be related to the Wipr 2 content blocker.
Removing that. Caution to anyone else who uses it.
Apologies to Meta.
I’m confused as to how a content blocker could cause this. Could someone more knowledgeable than me elaborate?
Good to know. thank you!
That does not sound plausible at all, wipr is an adblocker. No adblocker should be causing this. If it's spoofing your JS fingerprint and Meta uses that for suggesting accounts, wow would that be ridiculous.