I just lost almost all of my sponsor progress too 😠 Career progress appeared to have been reset, but after restarting the game, the career events were back to normal.
Attempting to complete a single objective for a sponsor doesn't trigger the complete status, as it used to previously when the odd one would show as reset. Now they're almost all at zero again (but linked events are still unlocked from previously completed sponsors)
Things to note:
When I started the game before this bug happened, I noticed it said I required an active EA account. I closed the game and re-opened it, and it said it again, so I just continued any way.
This happened exactly after I completed a carnage event in event creator, to complete the final part of the DLC "Achivee" sponsor. The end screen showed completion of a different sponsors objective. I then went to the Team sponsor page to select a new one, and it shows them reset, and a different sponsor was selected than the one I had assigned.