My team are connected and used different people? i can't understand

I had a team of my own and I haven't been in for a while. When I logged in via fb link, I realized that someone else has been using my team for a long time (game language has changed, player developments, package amounts, federation, team and manager name change). only the stadium name is original. I don't remember if I made the gmail connection before. When I look at the FB security details, there is no foreign device. I don't know how this could have happened.

Question : How can we save my team (club shop is important to me)?
📌 Is there a method to reset connections other than Facebook connection??
NOTE: I can share top eleven id (SS) privately with the mod/admin.
I haven't never shared my password or e-mail.

Hi Manager, sorry to hear that. Could you please share with me in a direct message your Manager ID so I can investigate it further? Thanks you!