Lost progress - Xbox
Many other unresolved threads about this so my hopes aren't high, but I had the bug causing my account to "reset" a year or more ago. Other suggested fixes such as opening other EA apps or playing matches haven't helped.
Characters still look like they are a high level if I haven't used them since the "reset", but once I play a match with them they revert to level 1 and begin leveling from there.
This also has caused me to be permanently locked out of earning certain milestone rewards, as the milestone has been marked "complete" and can't be done again, yet the associated cosmetic is locked.
Attached pictures are a level 38 Han Solo with no star cards unlocked (If I play a match with him he will go back to level 1), a picture showing that I have completed the milestone for the smuggler han outfit, and a picture showing that the smuggler han outfit is still locked.