Firefox is just another US-corporate product with an ‘open source’ sticker on it.
Their version 128 update has auto checked a new little privacy breach setting.
If you still use a corporate browser, at least do some safety version! We mainly use @librewolf based on firefox. (yes, we know, a stable european or even non-US browser is still considered ‘futuristic’ in europe)
It has sync, but you need to enable it. It’s in the settings, on the special librewolf page