and since dev.meta.ai supports meta account sign-up and log-in for individual users, you'd see this. As for the other accounts, has anyone else used this same browser or laptop before (e.g. shared device), so it must have cached previous sessions or accounts used from the same device.
try to clear the browser cache and session cookies. and it should be gone.
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.
The WIPE/privacy extension developer is using a pre-existing(hard-coded or generated) fingerprint to “mask” the user from meta .
Meta implemented a quality of life feature powered by the ability to set cookies and track you across the web of course and help users with forgotten accounts to unify them - but not a security issue you cannot do anything unless you are proving access governed by standard auth protocols ; the extension developer’s hack to mask created a broken experience because of the reused IDs.
Adblockers can create unintended effects , it is hard to reverse engineer complex platforms like meta and also hard to keep up to date with billion dollar companies code updates by small indie teams of volunteers ; doesn’t mean we shouldn’t use them, just be aware that it may happen when enabled