Missing window border on some flatpak apps

Since the last update, just some (!) flatpak apps are missing the window borders. Some work/look as they should. It seems to be random, but the affected apps stay the same.

I already changed the theme to other random ones and back to standard adwaita. Remains the same. The adwaita theme is installed via pacman and flatpak.

Anyone has an idea, what I can do?

update: It may have to do with some dependencies from the dev side. There was a spotify update and it now has a border. two other apps are still missing it.

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After some updates the flatpak apps for Typora and Spotify still missing their borders.
Signal, GIMP flatpaks etc. are looking as they should.

There are no error messages in Termial. journalctl just says (for all flatpak apps)

Error connecting to Touchégg daemon: Could not connect: Connection refused

since this is for gestures, I doubt that this is an issue.

All apps and system are up to date. Different Kernel (5.13 vs. 5.15) makes no difference.
I use wayland on GNOME 41.2.

Shell and App themes are the same on adwaita_dark standard.
org.gtk.Gtk3theme.Adwaita-dark/x86_64/3.22 is installed for both, regular and flat apps.

Noone got any idea?
Is it a “to do” for the devs or can I do something?

It would be useful if you could provide a screenshot of the problem: