Not sure what happened but I've been running Steam games using MANGOHUD=1 gamemoderun %command% and it's been working fine with Mangohud. Suddenly, no Mangohud. Mangohud still works with Lutris.

I am using the Flatpak version so I looked at my history and there haven't been any updates to the Steam or Mangohud Flatpaks when the breakage occurred. Nothing relevant is logged out if I run Steam using flatpak run com.valvesoftware.Steam. Inside Steam there have been a few updates, including an update to the common redistributable and that may have been around the time this broke. The only other thing I see is that Gnome updated some Flatpak stuff recently as well.

System wise I am on OpenSuse Tumbleweed using KDE Plasma 6. Any tips for debugging further?

Relevant Flatpak packages

Name                              Application ID                                Version  Branch       Installation
Valve Corporation                 com.valvesoftware.Steam                       1.0.0.79 stable       system
Mesa                              org.freedesktop.Platform.GL.default           24.0.3   22.08        system
Mesa (Extra)                      org.freedesktop.Platform.GL.default           24.0.3   22.08-extra  system
Mesa                              org.freedesktop.Platform.GL.default           24.0.3   23.08        system
Mesa (Extra)                      org.freedesktop.Platform.GL.default           24.0.3   23.08-extra  system
Mesa                              org.freedesktop.Platform.GL32.default         24.0.3   23.08        system
Mesa (Extra)                      org.freedesktop.Platform.GL32.default         24.0.3   23.08-extra  system
MangoHud                          org.freedesktop.Platform.VulkanLayer.MangoHud 0.6.8    21.08        system
MangoHud                          org.freedesktop.Platform.VulkanLayer.MangoHud 0.7.1    23.08        system
gamescope                         …g.freedesktop.Platform.VulkanLayer.gamescope 3.14.2   23.08        system
Freedesktop SDK                   org.freedesktop.Sdk                           23.08.14 23.08        system
GNOME Application Platform versi… org.gnome.Platform                                     45           system
GNOME Application Platform versi… org.gnome.Platform                                     46           system
i386                              org.gnome.Platform.Compat.i386                         45           system
Breeze GTK theme                  org.gtk.Gtk3theme.Breeze                      6.0.3    3.22         system
Adwaita theme                     org.kde.KStyle.Adwaita                                 6.5          system
KDE Application Platform          org.kde.Platform                                       6.5          system
DXVK                              org.winehq.Wine.DLLs.dxvk                     2.3      stable-23.08 system