Created attachment 1623832 [details]
The journal from the affected computer.

Description of problem:

I freshly installed Fedora 31 Live (Beta) (with all updates) on a brand new T580 and wanted to set up multiple monitors. However, each attempt to change the primary display from the built-in one resulted in Gnome Control Center crashing.
On Xorg, no such problem appeared and I could set up the monitors as desired.

I am using the ThunderBolt 3 Docking Station.


Version-Release number of selected component (if applicable):
gnome-control-center-3.34.1-2.fc31.x86_64

How reproducible:

Always

Steps to Reproduce:
1. Connect external monitors to the docking station.
2. Connect laptop to the docking station.
3. Start laptop and log into a Gnome session (wayland)
4. Run GDC.
5. Go to Display page and try to select a different primary monitor.
6. GDC crashes.

Actual results:

GDC crashes and external monitors cannot be added on a wayland session, so they are unusable.

Expected results:

Everything works like expected (like in a xorg session).

Additional info:

I found this in journal:
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Oct 09 15:58:53 localhost.localdomain audit[2612]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=2612 comm="gnome-control-c" exe="/usr/bin/gnome-control-center" sig=11 res=1
Oct 09 15:58:53 localhost.localdomain kernel: gnome-control-c[2612]: segfault at 38 ip 00005650dae24bee sp 00007fff88023140 error 4 in gnome-control-center[5650dadd8000+122000]
                                                              #0  0x00005650dae24bee cc_display_mode_dbus_is_supported_scale (gnome-control-center)
                                                              #1  0x00005650dae24d35 is_scaled_mode_allowed (gnome-control-center)
                                                              #2  0x00005650dae217fc cc_display_settings_rebuild_ui (gnome-control-center)
                                                              #3  0x00005650dae222f7 cc_display_settings_set_selected_output (gnome-control-center)
                                                              #4  0x00005650dae1aed0 set_current_output (gnome-control-center)
                                                              #5  0x00005650dae1bd56 on_output_selection_combo_changed_cb (gnome-control-center)
                                                              #37 0x00005650dadf3059 main (gnome-control-center)
                                                              #39 0x00005650dadf325e _start (gnome-control-center)
Oct 09 15:58:55 localhost.localdomain abrt-notification[2702]: Process 3182 (gnome-control-center) crashed in cc_display_mode_dbus_is_supported_scale()
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