I've finally been able to get it working by using David Woodhouse's packages built from the latest release, from his website:
www.infradead.org OpenConnect VPN client. <https://www.infradead.org/openconnect/packages.html> VPN client compatible with Cisco AnyConnect SSL VPN 🔗 https://www.infradead.org/openconnect/packages.html <https://www.infradead.org/openconnect/packages.html> then to his latest git HEAD repo: software.opensuse.org Install package home:bluca:openconnect / openconnect <https://software.opensuse.org/download.html?project=home%3Abluca%3Aopenconnect&package=openconnect> 🔗 https://software.opensuse.org/download.html?project=home%3Abluca%3Aopenconnect&package=openconnect <https://software.opensuse.org/download.html?project=home%3Abluca%3Aopenconnect&package=openconnect> Adding the repo and installing manually works the best. It was important to remove each of the packages: libopenconnect5, openconnect, network-manager-openconnect, and network-manager-openconnect-gnome. Then, check `apt-cache policy <pkg_name>` and install all 4 packages again, specifying the version for each, for example: apt install openconnect=9.12+201+gf17fe20-0+284.110 libopenconnect5=9.12+201+gf17fe20-0+284.110 network-manager-openconnect=1.2.10+7+g030a3a9-0+101.463 network-manager-openconnect-gnome=1.2.10+7+g030a3a9-0+101.463 I thought I could get away with just installing network-manager-openconnect-gnome=1.2.10+7+g030a3a9-0+101.463 but apt complained about wrong version for network-manager-openconnect. However, when I specified the version for both, it happily grabbed openconnect and libopenconnect5 from Debian repos instead of David's, and the issue remained unresolved. Be sure to carefully watch which version's apt downloads and installs! There's hopefully a nice way to configure this in apt so the packages only upgrade from the repo they were installed from, or something. For now I'm happy to have a working NM-plugin again and need to catch up on my work!
