Heavy stutter with current flatpak version

[kathoum]

Game information
Grim Dawn
edit: also happens in Skyrim

Distribution name and version where applicable
Debian trixie/sid
Kernel version: 6.11.4-1

Flatpak info
% flatpak --version
Flatpak 1.14.10
% flatpak --gl-drivers
default
host

Problem description
After upgrading application to version 1.0.0.81 via flatpak, there is heavy stutter in game when the frame rate drops below the monitor refresh rate, when in Fullscreen or Borderless Window mode.

Links to desktop recording:
https://streamable.com/pmem5r
https://drive.google.com/file/d/1N1gE1YHXDZSuPa6HcAOPyT7fDXm486Gk/view

GPU: Radeon RX 6600 XT (amdgpu driver)
Desktop environment is Plasma 5.27.11 (Wayland), compositor is kwin.

Switching to X11 has no effect.
Changing vsync settings in game or in KWin has no effect.
Enabling/disabling adaptive sync has no effect.
Issue does not happen when game is in Windowed mode.
Issue does not happen with application version 1.0.0.79 (commit 173cd565 in flathub).

Does this issue reproduce with native Steam
Not tested