SEGFAULT when reconnecting the 2nd of 2 monitors

Step to reproduce this issue:
Connect 2 monitors to a single GPU
Launch xfce4-settings-manager, go to Display and select the 2nd monitor (see the screenshot below)
Disconnect the 2nd monitor from the GPU
Reconnect the 2nd monitor to the GPU
Core was generated by `xfce4-display-settings --socket-id=10486978'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  display_setting_resolutions_populate () at xfce4-settings-4.16.3/dialogs/display-settings/main.c:911
911	           if (output->pref_width == modes[n].width

(gdb) bt
#0  display_setting_resolutions_populate () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:911
#1  display_settings_combobox_selection_changed () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:1532
#2  0x00007f9a88119ac7 in g_cclosure_marshal_VOID__VOIDv () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/gobject/gmarshal.c:165
#3  0x00007f9a88117669 in _g_closure_invoke_va () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/gobject/gclosure.c:893
#4  0x00007f9a88132483 in g_signal_emit_valist () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/gobject/gsignal.c:3406
#5  0x00007f9a88132622 in g_signal_emit () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/gobject/gsignal.c:3553
#6  0x00007f9a8880164b in gtk_combo_box_set_active_internal () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gtk/gtkcombobox.c:3855
#7  0x00007f9a8880439c in gtk_combo_box_set_active () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gtk/gtkcombobox.c:3779
#8  0x0000555a379d8320 in display_settings_combobox_populate () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:1760
#9  0x0000555a379de377 in screen_on_event () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:2575
#10 0x00007f9a885f2a3e in gdk_event_apply_filters () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gdk/x11/gdkeventsource.c:79
#11 0x00007f9a885f2db1 in gdk_event_source_translate_event () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gdk/x11/gdkeventsource.c:205
#12 _gdk_x11_display_queue_events () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gdk/x11/gdkeventsource.c:341
#13 0x00007f9a885b3a49 in gdk_display_get_event () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gdk/gdkdisplay.c:442
#14 0x00007f9a885f2af2 in gdk_event_source_dispatch () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gdk/x11/gdkeventsource.c:363
#15 0x00007f9a87dd879b in g_main_dispatch () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/glib/gmain.c:3417
#16 g_main_context_dispatch () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/glib/gmain.c:4135
#17 0x00007f9a87dd8a88 in g_main_context_iterate () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/glib/gmain.c:4211
#18 0x00007f9a87dd8dd3 in g_main_loop_run () at dev-libs/glib-2.72.3/work/glib-2.72.3-abi_x86_64.amd64/../glib-2.72.3/glib/gmain.c:4411
#19 0x00007f9a888f7d2d in gtk_main () at x11-libs/gtk+-3.24.34-r1/work/gtk+-3.24.34/gtk/gtkmain.c:1329
#20 0x0000555a379dcf50 in display_settings_show_main_dialog () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:3963
#21 0x0000555a379d6a96 in main () at xfce-base/xfce4-settings-4.16.3/work/xfce4-settings-4.16.3/dialogs/display-settings/main.c:4366