Folks, unacceptable though this may be, I am not that surprised. VDI is a relatively new service, and it's the first time it's being stress-tested (meaning many students are using it for the first time). It's yet another frustration of dealing with covid. The IT support people are doing their best to fix it. In the meantime, please stay positive and try alternatives. VPN-ing into EPFL and ssh-ing into one of the INF3 servers (with the -X option) should work. Let us know if you encounter further problems. And stay positive!