I am probably not out of the ordinary on this - I have Destiny 2 on PS4 (Main), Steam and Blizzard, along with XBox linked from Destiny 1 days. I log into Bungie.net with my XBox account (since I remember that password the best), so that is always Authenticaed when I go to the first screen for authentication. I can then Authenticate on PS4 and Steam without issue, but when I go to autthenticate Blizzard it is invalidating the PS4 and Steam authentications, and if I try to re-authenticate either of those it knocks the Blizzard one back out of authentication. This makes getting off of the first screen impossible at the moment to specify which characters I want to save between the platforms.