I have the same problem. C++ example runs fine but the Python example will not run. I just received the Navio 2 and set it up and tested the ardupilot and connected it to groundstation. Everything else has worked so far. I ran emlidtool test and i ran the gps example and took a screenshot.
I tried it about a dozen times and let it sit for awhile after issuing the command. It is like it is hanging and waiting for something. One time it did put out a single line of GPS data. But i could not repeat this. Again it’s sitting by the window and the GPS worded fine in ground station and the C++ example worked fine so it is getting a fix.
no, i stop the C++ script. Also you have to turn off the ardupilot. It lets you know you can not check the sensor with the ardupilot running. Can the problem be something with the latest Rpi4 Raspbian OS updates? I installed everything fresh last month when i got the navio. It sounds as if it had been working previously for other users.