Some flatpak apps fail to launch on systemd

Describe your issue

Currently on postmarketOS with systemd flatpak apps either take an extremely long time to launch (upwards of a minute) or fail to launch completely.

It also seems that specifically GTK4 apps freeze or crash often after launching.

What's the expected behaviour?

Flatpak apps launch (nearly) as fast as APK apps

What's the current behaviour?

Flatpak apps take a long time to launch or fail outright.

How to reproduce your issue?

Install a Flatpak from Flathub and attempt to launch it.

(Freetube, Discord, and sometimes Tuba are the apps I have found to fail so far, but there are probably many more.)

What device are you using?

generic-x86_64

On what postmarketOS version did you encounter the issue?

• edge (master branch)

• v24.12

• v24.06 (supported until 2025-01-23)

• I confirm that the issue still is present after running sudo apk upgrade -a

On what environment did you encounter the issue?

Environments

• GNOME Shell on Mobile
• Phosh
• Plasma Mobile
• Sxmo (Wayland/Sway) Please post the output of sxmo_version.sh
• Other: GNOME Desktop

Which init system are you using?

• OpenRC
• systemd

How did you get postmarketOS image?

• from https://images.postmarketos.org
• I built it using pmbootstrap
• It was preinstalled on my device

What's the build date of the image? (in yyyy-mm-dd format)

Additional information

Discord Flatpak (Doesn't Launch):

Disabling updates already done
Assertion 'p' failed at src/libsystemd/sd-event/sd-event.c:181, function event_origin_changed(). Aborting.
/app/bin/com.discordapp.Discord: line 43:     5 Aborted                 (core dumped) env TMPDIR="${XDG_CACHE_HOME}" zypak-wrapper /app/discord/Discord --enable-speech-dispatcher "${FLAGS[@]}" "$@"
2025/01/19 13:48:47 socat[3] W exiting on signal 15

Freetube Flatpak (Doesn't Launch):

Assertion 'p' failed at src/libsystemd/sd-event/sd-event.c:178, function event_origin_changed(). Aborting.

Tuba Flatpak (Crashes):

MESA-INTEL: warning: Haswell Vulkan support is incomplete
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:752: FINISHME: support YUV colorspace with DRM format modifiers
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:783: FINISHME: support more multi-planar formats with DRM modifiers

(dev.geopjr.Tuba:2): Gtk-WARNING **: 13:51:33.579: Unable to retrieve the Flatpak portal version: Timeout was reached

Blanket Flatpak (Crashes):

MESA-INTEL: warning: Haswell Vulkan support is incomplete
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:752: FINISHME: support YUV colorspace with DRM format modifiers
MESA-INTEL: warning: ../src/intel/vulkan_hasvk/anv_formats.c:783: FINISHME: support more multi-planar formats with DRM modifiers

(python3:2): Gtk-WARNING **: 13:53:35.889: Unable to retrieve the Flatpak portal version: Timeout was reached