Steam can't start non-Steam games imported by the Heroic Games Launcher.

**Game information**
Any game added to Steam by the Heroic Game Launcher.

**Distribution name and version where applicable**
Ubuntu 23.04 (Lunar Lobster)

**Flatpak info**
My flatpak version : `flatpak --version`
My gl-drivers : `nvidia-525-105-17
default
host`

**Problem description**

Flatpak Steam doesn't launch non-Steam games imported by the Heroic Games Launcher, I reckon allowing Steam to acces /home files would make it work but it cannot be done as allowing this makes Steam unable to launch.
**Does this issue reproduce with native Steam ?**

No, native Steam launches any non-Steam game imported to it.