Hi Richard, so I’ve blown the sd card away and re-installed 64 bit pi os. I followed the updated instructions without n_gsm and on the first occasion it worked. I then rebooted the pi, and gsmMuxd consistently failed.
I blew the os away again and re-installed a fresh image. I then re-installed gsmMuxd. Before I ran gsmMuxd for the first time I checked the contents of pts file which were two files named ‘0’ and ‘ptmx’.
I then ran gsmMuxd and there were files named 0 1 2 3 ptmx present. I then configured gsmMuxd to start on boot, and rebooted the pi to test. After reboot I waited a period, then checked the pts folder and only files ‘0’ and ‘ptmx’ were present. I then manually ran gsmMuxd and it failed again. It seems after a reboot gsmMuxd is failing for me. I am using the current raspberry pi bullseye 64 bit release, and conduct a update prior to installing gsmMuxd. The pi sugar occupies the I2C pin, not the serial pins unless I am mistaken, and prior to a reboot, I was able to use minicom to issue AT commands to the modem and received expected outputs, so that seems to be a non issue hopefully…
Sorry for the long response, do you have any other suggestions to get the board working?