Bought a key yesterday, I can use it just fine but if Reborn Buddy crashes I get max session message but I'm unable to close session on the portal since they key doesn't show there.
If you used a different email in the past it may have been automatically associated with that email. You can also edit globalsettings.json and change KillOldAuthSessionOnMaxSessions to true and then it will automatically kill the session.
Still the same emailed used I checked. Doesn't matter, changing the setting is good enough for me so thanks for that.