- I'm using Kubuntu 21.10 with kernel 5.13.0-22.
- It happens with both Ethernet, 2.4GHz Wi-Fi, and 5GHz Wi-Fi connections (two separate Wi-Fi networks).
- Things worked fine until this week.
- Rebooting the laptop does not help.
- The Windows installation on the same laptop does successfully connect.
- My Kubuntu live USB does successfully persist its connection through sleep, so it's something with my OS install.
- Rebooting the modem always lets me reconnect, but closing and re-opening the laptop lid will trigger the problem again.
- Removing the remembered connections from System Settings and re-adding them does not help.
I suspect this has something to do with DHCP business and assigned IPs, but I don't know anything about networking, so I'm not sure how to test or examine for that. I did install and then uninstall a large number of packages over the last 2 weeks, so I suspect I broke something in the process, e.g. by installing some package that replaces some built-in features, then uninstalling it without restoring the original's settings. Looking through my history, DNSmasq, Caddy, and Jellyfin-Server are the three packages that seem most obviously networking-related that got installed and removed lately.
What settings, services, potentially missing packages, etc should I look at first to help me diagnose this problem?
