Network Manager (or networkmanager) is a comfortable GUI app to switch between internet connections in Linux. The more recent versions of it seem to misbehave more and more, in my experience failing mainly with older Android modems. Here’s a workaround that may help.
The workaround requires dhcp as described at Manjarowiki, but the instructions are a bit different.
- Determine the devices:
ls /sys/class/net
This gives you normally three devices on computer to connect to internet: wifi, ethernet, and something called lo. - Connect the Android phone, switch it to make modem, and see if it Network Manager fails. If it fails, move on to the next step.
- Determine the devices again:
ls /sys/class/net
This time it should list four devices. The fourth is your modem. It’s the one to go for with dhcp. - As root, type
dhcpcd enp*
where enp* should be completed as your fourth device appeared in the previous step. - Now there should be internet 🙂
The Manjarowiki instructions also include a step how to make the device permanent in systemd across reboots, but this is not feasible with mobile phone modem, as it sometimes gets differently assigned. The enp* identifier will be different, so it cannot be made permanent.