Hi. Have you read this? Do you have the same problem or is everything ok on your installation?
https://forum.proxmox.com/threads/remote-spice-access-without-using-web-manager.16561/page-3#post-234122
Thanks for a hint ...
https://forum.proxmox.com/threads/remote-spice-access-without-using-web-manager.16561/page-3#post-234122
Thanks for a hint ...