OK, I can repro this on one machine but not another (not sure what the difference is yet).  For the record, journalctl is spammed with error like the following when it does happen.

Mar 23 09:00:01 xt2-17 konsole[12421]: g_application_get_application_id: assertion 'G_IS_APPLICATION (application)' failed
Mar 23 09:00:01 xt2-17 konsole[12421]: g_variant_new_string: assertion 'string != NULL' failed
Mar 23 09:00:01 xt2-17 konsole[12421]: g_application_get_application_id: assertion 'G_IS_APPLICATION (application)' failed
Mar 23 09:00:01 xt2-17 konsole[12421]: g_variant_new_string: assertion 'string != NULL' failed
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-fallback-icon-theme
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-icon-sizes
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-alternative-button-order
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-show-input-method-menu
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-show-unicode-menu
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-timeout-initial
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-timeout-repeat
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-timeout-expand
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-color-scheme
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-touchscreen-mode
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-tooltip-timeout
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-tooltip-browse-timeout
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-tooltip-browse-mode-timeout
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-keynav-cursor-only
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-keynav-wrap-around
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property color-hash
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-file-chooser-backend
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-print-backends
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-print-preview-command
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-recent-files-limit
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-fontconfig-timestamp
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-sound-theme-name
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-enable-input-feedback-sounds
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-enable-event-sounds
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-enable-tooltips
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-toolbar-style
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-toolbar-icon-size
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-auto-mnemonics
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-visible-focus
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-entry-password-hint-timeout
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-menu-bar-popup-delay
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-scrolled-window-placement
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-can-change-accels
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-menu-popup-delay
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-menu-popdown-delay
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-color-palette
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-im-preedit-style
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-im-status-style
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-titlebar-middle-click
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-titlebar-right-click
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-enable-primary-paste
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-keynav-use-caret
Mar 23 09:00:01 xt2-17 konsole[12421]: GtkSettings Cursor Theme: Unsupported GDK backend
Mar 23 09:00:01 xt2-17 konsole[12421]: unknown property gtk-fallback-icon-theme