Console doesn't work with 3.9 and Proxmox

When connecting to the console of a VM located on Proxmox, the console no longer connects. No error messages are given, just a “Loading” message. On the Proxmox host we see a connection attempt and it times out.

Expected outcome:
Console to show up. Worked fine prior to 3.9 update (worked in 3.8).

Foreman and Proxy versions:
Foreman 3.9

Foreman and Proxy plugin versions:

Distribution and version:

Other relevant data:

You need to follow additional steps in order to make console for Proxmox work as it uses VNC console. Here is the docs for it: Provisioning Virtual Machines in Proxmox - orcharhino documentation

I hope it helps.

It worked before the upgrade. Looking at the source inspecting in Chrome the data-host variable is being left empty in the file generated by vnc.html.erb.