Sometimes when I plug in an external monitor via HDMI, my OS freezes up. Sometimes it happens immediately, other times it happens later. This happens about 60% of the time. I'm running a 2017 Dell XPS 15".
Not even sure where to start troubleshooting this problem. Are there some crash logs or something?
When it freezes up, try to get to the terminal: Ctrl+Alt+F2. If it works, have a look at the following logs, /var/log/lightdm/lightdm.log and /var/log/syslog. Also, try restarting lightdm service:
sudo service lightdm restart
Those are not the only logs to check, but it's a good start. You can either try to reproduce the problem or check the logs by date, in case you still remember the last it happened. Let me know if you need help.
