Loose flight connection while in flight

While in a session, FSR loose the flight connection. I can't say "sometimes" because I bought it yesterday, make 2 flights, and it happens twice. I saw similar posts here, but without any solving solution.

Any idea of what happens ?

Related question : does FSR uses FSUIPC ? should I look in that direction to solve the issue ?

thanks

Win 11, FSR 2.1.0, FSUIPC 7.3.04