Hi by USB3 do you mean USB 3.0 the blue plugs in the Pi4? 

Doing both cgps and gpsmon when the gps dongle is only connected works fine it all stops working once I add the ZWO camera which is a USB 3.0 blue connection(tired both pulgs as well still crashed the gps). I will try connecting everything on the a USB2.0 with a hub and see if that helps 

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