I need help

Im playing this game for 6/7 years. And for some reasons i couldn't play last month. 4 days ago i opened the game and when I checked my history it shows someone playing my games for some days. I have gmail, fb and montoon accounts. And also have 2 step verification.

So when i check the device where logged in it shows that a Realme devie are logging in . So i tried to remove the account. It shows me that i only can remove it with my trusted device. And it also shows me the trusted device code . When i search the code it shows my current devide. Thats mean my current device is my trusted device. Still i cant logged out that Realme device.

The person is still playing this game everyday. I need help to remove the account and sorry for my bad English