The VDI access problem has returned, we have filed a ticket and awaiting IT services to respond.
In the meantime, you can try the INF3 solution: ssh *some* INF3 machine (using the "-X" flag for graphical-depending applications like Wireshark). Please keep in mind that i) you must connect to the VPN before accessing the INF3 machines, and ii) you may have to try different INF3 machines as they might be turned off outside the lab session time slot.