I spent yesterday doing the same thing, researching how ID'S work. At least someone on another thread got confirmation 13 hours ago that its an issue with EAs authentication and they are aware of it but that's all we got.
Yeah, it's pretty shocking.
I've been aggressively trying to tackle this issue for the past few days spending close to 10-hours in various streams of EA tech support channels, and I think I'm getting close to finding the cause.
My current theory is that after logging into Battlefield 6 on launch day (which would have used my account credentials to generate an authentication token), I changed my account details. Which was fine while my authentication token was valid.
Once that token expired however (potentially 24 hours later), Battlefield 6 was no longer able to create a valid authentication token which is leading to the error you're seeing.
You might ask "But why is it not using my current account credentials to generate the auth-token?"
I dug deeper, and found that multiple iterations of my EA ID were able to log into my account using my current password.
I suspect this is a back-end bug that could be causing all kinds of authentication troubles internally.
Unfortunately, EA doesn't seem to want to take this legitimate cyber-security risk seriously... So here we are. Public forums.
Check out the forum post below:
https://forums.ea.com/discussions/ea-app-technical-issues-en/security-vulnerability---multiple-ea-ids/12763070
