Openfortivpn connection is established apparently, routes are created, but the connection is unusable, can't reach any of the services behind the VPN, ping them does not work. The connection seems to be established, as reported by the Network Manager applet, but will disconnect after a while, like 10-20 mins (may there be a timeout, actually?). It worked fine previously to this Network Manager version (5.27.5). Using openfortivpn cli works perfectly, so there may be affected its integration with the Network Manager (well, on both sides...). Problem reported here: https://bugs.kde.org/show_bug.cgi?id=472491 https://github.com/adrienverge/openfortivpn/issues/1128
Sorry to forget to specify it is KDE Plasma related, so far.
I've created a new bug report here: https://bugs.kde.org/show_bug.cgi?id=472491, https://github.com/adrienverge/openfortivpn/issues/1129
I have the same problem in Gnome. openforti works fine from the command line, but does not work in networkmanager.
For others looking, while networkmanager-fortisslvpn did not work, I was able to use networkmanager-openconnect in networkmanager in Gnome to connect to the Forti VPN.