If there are issues saving logs to a USB storage device, check the logs to confirm whether the device is working properly. The following example indicates the USB storage device might need to be reformatted or replaced.
Fri Jan 20 14:22:22 2023|WARN|mountfilesystem|Failed to mount USB drive, err=Command '['/bin/mount', '/dev/sda1', '/var/media', '-o', 'dmask=000,fmask=111']' returned non-zero exit status 255. Fri Jan 20 14:22:25 2023|INFO|qxdmlog|Modem log stop Fri Jan 20 14:22:25 2023|WARN|qxdmlog|No log file found in /var/media Fri Jan 20 14:22:25 2023|INFO|qxdmlog|No log file found Fri Jan 20 14:22:25 2023|INFO|qxdmlog|saveLogSetInfo, fn=None Fri Jan 20 14:22:25 2023|WARN|usbupgrade|Failed to mount USB drive