I believe it's because the package is marked as manually installed now. Now, I strongly believe that all these problems are happening because at some point you removed ubuntu-minimal. It's a meta package used to install a minimal set of utilities required by all Ubuntu installations. Netplan is part of it.
Try to install ubuntu-minimal, it should resolve the problem. ** Changed in: netplan.io (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2083699 Title: netplan.io gets removed on apt autoremove To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/2083699/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs