@bogdantomasciuc
Thanks for trying it! This one comes from upstream Xen Orchestra, not the installer. A change in XO's connection library (around 2026-09-09) left servers set to connect through an HTTPS proxy that supports HTTP/2, such as XO Proxy, stuck in Connecting. Vates fixed it in #10507 and released it in XO 6.9.1 (2026-10-05). That's also why the other project broke the same way.
Running --update should pull the fix, since the installer builds from master by default. If servers behind the proxy still won't connect after updating, please open an issue with what the Servers page shows and I'll dig in.
Side - note the disable license check is no longer needed as that appears not to be gated by the license check.
I have pushed these changes to the Dev branch. You should be able to switch to the dev branch and run the update ...
git fetch origin
git switch dev
./install-xen-orchestra.sh