Problems with GPS not activated

Hello everyone with any version of apm 2.6 or 2.8 and e tested more than 4 brand new apm, also more than 4 new GPS

the problem turns out that everything is working correctly, once I am in full flight and supposedly I give to loiter or rtl the drone is still stabilized, does not change to another mode.

I connect the drone to the pc to the MP and change the flight mode example to loiter, rtl etc etc and if the change appears it changes but the gps or rtl mode is not really working.

I have tried many versions of MP, as well as new and previous fimeware, and tried changing apm and gps and neither.

I can not activate the loiter or rtl mode, or any other way that is not stabilized, the compass is calibrated and placed in 12c and also under the gps port, and the jum changed from position 1 to 3 and vice versa, I’ve done everything I’ve been doing for years without problems, but now I can not use other flight modes, I’ve also tried if it was the station and it’s correct with 3 stations the same thing happens