There seems to be an issue with
Urza, Academy Headmaster in Freeform EDH. Whenever you try to start a freeform commander game with him in the command zone, nobody will draw any cards. The game is simply stuck. If you choose to play with him in your deck, and you use a different commander, it becomes possible to start the game. However, it is not possible to search your library. Whenever you try to search it, nothing happens. Unfortunately, I never got to see what happens, if you indeed draw him. (i.e.) Whether the game freezes.
This issue occurred for the first time with version 1.4.33V2, and continued to be in 1.4.33V3. IIRC,
Urza, Academy Headmaster didn't have an image assigned in version 1.4.33V1 (he worked perfectly fine at that point in time). So I used a custom image. At first I thought that this image may have caused this predicament. However, deleting the image, and downloading the new image did not change the described behaviour. The game still froze with him as commander. I hope this information help you in any kind of way.
Best regards
Hoac
https://github.com/magefree/mage/issues/5589