After following the instructions on the official Android Apps page and ignoring the warning that "this" was about to happen, I did it anyway (mistake - listen to warnings). Essentially anbox is known to only work on certain supported phones.
The long and the short of it is that anbox doesn't work on the Xiaomi Poco M3 because there is a kernel module which is not available. The module creates a device /dev/binder1 which the upstart system appears to want to connect to an initialize and, well, it can't. But it doesn't give up, no no no. It retries forever and ever using a lot of CPU time and hence battery power, burdening NetworkManager with the impossible task of trying to "up" the anbox0 network adaptor.
Searching the web produces various recipes to uninstall anbox, none of which worked for me. Hence this page describing a simple, but overkill, atomic bomb method to completely nuking anbox.
The steps are quite simple. Use ssh to access email@example.com.
- Put the system's image in read/write mode (as described on the SDcard howto page).
- rm /etc/init/anbox*
- rm /usr/bin/anbox*
- rm -rf /home/phablet/anbox-data
- Put the system's image in read only mode (as described on the SDcard howto page).
The last thing to do is reboot the phone (which part of step 5 above.