Homeserver doesn't work with Element Desktop on Linux (Flatpak)

[bartvdbraak]

Steps to reproduce

1. Download and run flatpak run im.riot.Riot
2. Enter blender.org as homeserver instead of matrix.org
3. Error shows Homeserver URL does not appear to be a valid Matrix homeserver

Outcome

What did you expect?

blender.org should work since it works even if I run a native build locally or when I run other clients of Element:

What happened instead?

It gives an error.

Operating system

Gentoo 2.15 x86_64, 6.8.12-gentoo, KDE Plasma 5.27.11, KWin (Wayland)

Application version

1.11.75 stable, Rust SDK 0.7.1 (c8c9d15), Vodozemac 0.6.0

How did you install the app?

via KDE Discover 5.27.11

Homeserver

blender.org (should pick up https://matrix.blender.org from m.homeserver using .well-known delegation)

Will you send logs?

Yes