Kakute f4 mini ardupilot4.1.3 GPS cant work with telemetry


I got a new kakute f4 mini and wired with 3dr telemetry and gps. first, I cant get gps work properly, I tried serveral gps and different parameters, cant get 3d fix. but escept gps, everything is ok.
finally I found what’s the problemm really is, when I connect GSC via telemetry, GPS will lost data. if I dont connect gsc, even telemetry is powered on, gps get 3d fix very quickly. it seems telemetry data transmission messing the gps data. I disconnected GSC, gps can get 3d fix again.
anyone has ever such problem, I use 915M 3dr telemetry.