I have the same problem outside, I just didn't have a screenshot from when I tried then. I just found the message really confusing. Sometimes I get a more specific error like "GPS speed is 1.2 but needs to be 1.0", but this only happens inside.
Is there any way to monitor the GPS status better than what QGroundControl tells me? I've been playing with the Nuttshell over mavlink, but did not find any GPS related stuff in there yet. Currently I'm trying to get some more infos via MissionPlaner and u-center, but I have to mess with Windows for that :-(.
I should mention though that I've compiled from source and get a warning that my compiler version is too high (5.4.1). I'm not sure if that has any influence, but wanted to mention it nonetheless. Also I'm only using the internal compasses of the Pixracer, the compass which is part of the GPS module is not connected.