RDM Linux 2026.3.1.1 Flatpak crashes when closing an active SSH session; also observed while idle

Hello Devolutions Support,

Remote Desktop Manager for Linux terminates with SIGSEGV when I close an active SSH session. I have also observed a crash while leaving RDM running without interaction. Two captured crashes have the same native stack signature in g_object_remove_toggle_ref. The session-closing crash also occurred with X11 explicitly forced and the Wayland socket disabled for RDM.

Impact
The whole RDM process exits, interrupting my remote-session workflow.

Environment
- RDM version: 2026.3.1.1, x86_64
- Installation: system-wide Flatpak, origin "devolutions", branch "current"
- App ID: com.devolutions.remotedesktopmanager
- App ref: app/com.devolutions.remotedesktopmanager/x86_64/current
- App commit: 6a30b972e332f8fb3b5f4f073da55ebbc1ffe85d2e26aa6ae973340b21f78235
- App build date: 2026-10-02 22:02:45 UTC
- Desktop: KDE; session type: Wayland
- Runtime: org.gnome.Platform/x86_64/49, origin "flathub", system installation
- Runtime commit: 2bb946ea4ebb050f6a32f90e979feb975b08280d1ff1aac881dec3d1361ad84d
- Runtime build subject: Build of the GNOME Runtime from: 49.10-1-g75d7cf116
- Runtime build date: 2026-10-03 06:00:39 UTC
- libgobject/libglib reported in the crash: 2.86.5 (libgobject-2.0.so.0.8600.5)
- NVIDIA library present in the first core: libnvidia-glcore.so.615.71.09
- Host distribution, kernel, Flatpak version and KDE version: not yet collected

Steps observed to trigger the crash
1. Launch RDM.
2. Open and use an SSH session in RDM.
3. Close the active SSH session.
4. RDM can terminate with SIGSEGV instead of only closing the session.

Expected: The SSH session closes and RDM remains running.
Actual: The entire RDM process crashes and systemd records a core dump.

Frequency: Observed more than once, but not established to happen on every session closure. An additional idle crash was observed. I have not established whether this began with the October 2 update.

Crash evidence
Both cores identify this executable:
/app/lib/devolutions/RemoteDesktopManager/RemoteDesktopManager

First captured crash: 2026-10-07 14:14:33 CEST, host PID 26701, SIGSEGV.
Its symbolized native stack begins:
#0 g_type_check_instance_is_fundamentally_a (...) at ../gobject/gtype.c:3917
#1 g_object_remove_toggle_ref (object=0x55798d1c8360, ...) at ../gobject/gobject.c:4561
#2 0x00007f336174438f in ??? ()

Second captured crash: 2026-10-07 15:32:00 CEST, host PID 32109, SIGSEGV, on closing an active SSH session during the forced-X11 test.
Its symbolized native stack begins:
#0 g_type_check_instance_is_fundamentally_a (type_instance=0x56015b1aba30, fundamental_type=0x50 [GObject]) at ../gobject/gtype.c:3917
#1 g_object_remove_toggle_ref (object=0x56015b1aba30, notify=0x7f27fbc19b90, data=0x7f17a1c145b0) at ../gobject/gobject.c:4561
#2 0x00007f27ff713f7f in ??? ()
#3 0x00007f185acae7a0 in ??? ()
#4 0x0000000000000001 in ??? ()
#5 0x00007ffd332abad0 in ??? ()
#6 0x0000000000000000 in ??? ()

The faulting source line reported by GDB in both cases is:
node = lookup_type_node_I (type_instance->g_class->g_type);

The managed caller is not resolved by these native GDB traces. An invalid or already freed GObject is a hypothesis, not a confirmed root cause.

Troubleshooting completed
- Installed the GNOME 49 SDK and debug symbols to inspect the cores.
- Disabled GDB debuginfod retrieval and successfully obtained backtraces.
- Tested this launch command:
flatpak run --socket=x11 --nosocket=wayland --env=GDK_BACKEND=x11 com.devolutions.remotedesktopmanager
- RDM still crashed when closing an active SSH session under that launch configuration, with the same native stack signature.
- Queried the Devolutions remote using flatpak remote-info --system --log devolutions com.devolutions.remotedesktopmanager//current. It returned an empty History section, so no application rollback was tested.
- No native .deb/.rpm installation or runtime rollback has been tested.

Additional terminal messages during the forced-X11 run
(RemoteDesktopManager:2): Gtk-WARNING **: 14:30:37.594: Locale not supported by C library.
Using the fallback 'C' locale.
(RemoteDesktopManager:2): GLib-GObject-CRITICAL **: 14:30:53.233: ../gobject/gsignal.c:2437: signal 'response' is invalid for instance '0x7f17a80089b0' of type 'GtkWindow'

That warning occurred earlier in the run; a causal relationship with the later crash has not been established. Flatpak also reported reserved /etc certificate paths not being shared. GDB reported unavailable file-backed mappings and deleted memfd mappings, but successfully loaded the cores and resolved the two GObject frames.

Available diagnostic files
- rdm-backtrace.txt: first core, bt full and all-thread backtraces
- rdm-32109-backtrace.txt: second core, top 15 frames requested
- rdm-x11-test.txt: terminal output from the forced-X11 run

Please confirm whether this is a known RDM/GTK binding object-lifetime issue or a GNOME 49 runtime compatibility issue. Is there a fixed build or recommended workaround? If a managed stack trace is required, please provide the appropriate SOS/runtime-symbol collection steps for this exact Flatpak build.