Software Manager insists there is no network when there is.

I'll admit I do have unusual network configuration. But the bottom line is, EVERYTHING else is working normally, update manager, apt, aptitude, and all other networking apps work fine (Discord, Firefox, Steam, etcetc)

But mintinstall absolutely insists there is no network connection when I try to install any packages from it. When I open software sources and set the sources all works normally. Update Manager works normally. mintinstall can even regenerate the cache, lets your browse packages.

But as soon as I click 'install', it just says 'Cannot download packages whilst offline.'

My network is managed by networkd, it's all hardcoded in /etc/netplan files to configure some VPNs and static IP, then run some firewall rules out of an init.d script. NetworkManager only gets to see the wifi adapter in my machine, which is always just turned off.

I'm figuring mintinstall is relying on NetworkManager at some point to tell it's there's a valid network connection active but in my system NetworkManager has no valid connections to report as everything is managed by networkd instead.

Reproduce the install attempt on a system using networkd with no active NetworkManager connection, then trace how mintinstall decides whether the system is online. Compare that check with the successful cache regeneration and package browsing paths. Done means package installation no longer reports offline when networkd provides working connectivity.