Hello, I’m having similar issues to those previously seen – I couldn’t get the unit to work on 64 bit raspberry pi os, so reverted to 32bit which seemed better. I’m now struggling with gsmMuxd recieving the same MUX mode fail to function error seen two comments above. As part of fault finding I’ve blown it away (again) to a fresh os and am just trying to read serial data from the gps without multiplexing and cant get that to come through – cat /dev/serial0 just hangs and doesn’t return anything. Any hints? The pi is running a pisugar, could that be impacting things?