fps problem

hello I usally have around 60 ish fps and sometimes when I tab out and in it get locked to like 25 ish fps do anyone now how to solve this?

 

Do you have a Thrusmaster wheel and if you do, does this occur only wheel connected?

Or any other steering wheel or controller?

I had issue with Thrustmaster steering wheel, which was bit similar, but for me it was 3fps, but after moving computer few meters to new location and installing new Canon printer issue did dissappear, so far have not been able to make it happen again.

Also it was needed to have more than 1 vehicle in game for that to happen.