If the VDI is opened without maximizing the window size of the Web browser, resizing the VDI window later will not result in the correct resolution being displayed.

In this case, close the tab of the web browser in which the VDI is open, select "Restart" from the list of reservations, and try logging in again a few moments later.

(Note: How to reboot the virtual terminal)

Q:VDI has frozen.

https://www.iimc.kyoto-u.ac.jp/en/faq/ecs/vdi/post_232.html