This regression is caused by this commit: https://git.xfce.org/xfce/libxfce4ui/commit/?id=6d4ec5e After it, Commands Shortcut dialog's content is completely missing.
Simon Steinbeiss referenced this bugreport in commit d04fd596c403a0afc00ade84145d6fd508607b16 shortcut-dialog: Show dialog content (Bug #16338) https://git.xfce.org/xfce/libxfce4ui/commit?id=d04fd596c403a0afc00ade84145d6fd508607b16
Should be fixed. Lemme know if you notice anything else!