It looks like this is an LO issue. Looking at the example of insert table, the action is set to disabled:

$ gdbus call --session --dest :1.194 --object-path /org/libreoffice/window/88080484/menus/menubar --method org.gtk.Menus.Start [0]
([(uint32 0, uint32 0, [{':section': <(uint32 0, uint32 5)>}]), (0, 5, [{':section': <(uint32 0, uint32 6)>}]), (0, 6, [{'command': <'.uno:PickList'>, 'label': <'_File'>, 'submenu-action': <'win..uno:PickList'>, ':submenu': <(uint32 72, uint32 0)>}, {'command': <'.uno:EditMenu'>, 'label': <'_Edit'>, 'submenu-action': <'win..uno:EditMenu'>, ':submenu': <(uint32 73, uint32 0)>}, {'command': <'.uno:ViewMenu'>, 'label': <'_View'>, 'submenu-action': <'win..uno:ViewMenu'>, ':submenu': <(uint32 74, uint32 0)>}, {'command': <'.uno:InsertMenu'>, 'label': <'_Insert'>, 'submenu-action': <'win..uno:InsertMenu'>, ':submenu': <(uint32 75, uint32 0)>}, {'command': <'.uno:FormatMenu'>, 'label': <'F_ormat'>, 'submenu-action': <'win..uno:FormatMenu'>, ':submenu': <(uint32 76, uint32 0)>}, {'command': <'.uno:TableMenu'>, 'label': <'T_able'>, 'submenu-action': <'win..uno:TableMenu'>, ':submenu': <(uint32 77, uint32 0)>}, {'command': <'.uno:ToolsMenu'>, 'label': <'_Tools'>, 'submenu-action': <'win..uno:ToolsMenu'>, ':submenu': <(uint32 78, uint32 0)>}, {'command': <'.uno:WindowList'>, 'label': <'_Window'>, 'submenu-action': <'win..uno:WindowList'>, ':submenu': <(uint32 79, uint32 0)>}, {'command': <'.uno:HelpMenu'>, 'label': <'_Help'>, 'submenu-action': <'win..uno:HelpMenu'>, ':submenu': <(uint32 80, uint32 0)>}])],)
$ gdbus call --session --dest :1.194 --object-path /org/libreoffice/window/88080484/menus/menubar --method org.gtk.Menus.Start [75]
([(uint32 75, uint32 6, [{'action': <'win..uno:InsertDoc'>, 'command': <'.uno:InsertDoc'>, 'label': <'_File...'>}]), (75, 0, [{':section': <(uint32 75, uint32 1)>}, {':section': <(uint32 75, uint32 2)>}, {':section': <(uint32 75, uint32 3)>}, {':section': <(uint32 75, uint32 4)>}, {':section': <(uint32 75, uint32 5)>}, {':section': <(uint32 75, uint32 6)>}]), (75, 1, [{'action': <'win..uno:InsertBreak'>, 'command': <'.uno:InsertBreak'>, 'label': <'Manual _Break...'>}, {'command': <'.uno:FieldMenu'>, 'label': <'Fiel_ds'>, 'submenu-action': <'win..uno:FieldMenu'>, ':submenu': <(uint32 94, uint32 0)>}, {'action': <'win..uno:InsertSymbol'>, 'command': <'.uno:InsertSymbol'>, 'label': <'S_pecial Character...'>}, {'command': <'.uno:FormattingMarkMenu'>, 'label': <'Formatting Mark'>, 'submenu-action': <'win..uno:FormattingMarkMenu'>, ':submenu': <(uint32 95, uint32 0)>}]), (75, 3, [{'command': <'.uno:InsertPageHeader'>, 'label': <'He_ader'>, 'submenu-action': <'win..uno:InsertPageHeader'>, ':submenu': <(uint32 96, uint32 0)>}, {'command': <'.uno:InsertPageFooter'>, 'label': <'Foote_r'>, 'submenu-action': <'win..uno:InsertPageFooter'>, ':submenu': <(uint32 97, uint32 0)>}, {'action': <'win..uno:InsertFootnoteDialog'>, 'command': <'.uno:InsertFootnoteDialog'>, 'label': <'Footnote/Endnote_...'>}, {'action': <'win..uno:InsertCaptionDialog'>, 'command': <'.uno:InsertCaptionDialog'>, 'label': <'Caption...'>}, {'action': <'win..uno:InsertBookmark'>, 'command': <'.uno:InsertBookmark'>, 'label': <'Bookmar_k...'>}, {'action': <'win..uno:InsertReferenceField'>, 'command': <'.uno:InsertReferenceField'>, 'label': <'Cross-reference...'>}, {'action': <'win..uno:InsertAnnotation'>, 'command': <'.uno:InsertAnnotation'>, 'label': <'Comme_nt'>, 'accel': <'<Primary><Alt>c'>}, {'action': <'win..uno:InsertScript'>, 'command': <'.uno:InsertScript'>, 'label': <'S_cript...'>}, {'command': <'.uno:IndexesMenu'>, 'label': <'Inde_xes and Tables'>, 'submenu-action': <'win..uno:IndexesMenu'>, ':submenu': <(uint32 98, uint32 0)>}]), (75, 2, [{'action': <'win..uno:InsertSection'>, 'command': <'.uno:InsertSection'>, 'label': <'_Section...'>}, {'action': <'win..uno:HyperlinkDialog'>, 'command': <'.uno:HyperlinkDialog'>, 'label': <'_Hyperlink'>, 'accel': <'<Primary>k'>}]), (75, 5, [{'action': <'win..uno:InsertFrame'>, 'command': <'.uno:InsertFrame'>, 'label': <'Fra_me...'>}, {'action': <'win..uno:InsertTable'>, 'command': <'.uno:InsertTable'>, 'label': <'_Table...'>, 'accel': <'<Primary>F12'>}, {'command': <'.uno:GraphicMenu'>, 'label': <'_Image'>, 'submenu-action': <'win..uno:GraphicMenu'>, ':submenu': <(uint32 99, uint32 0)>}, {'action': <'win..uno:InsertAVMedia'>, 'command': <'.uno:InsertAVMedia'>, 'label': <'Mo_vie and Sound...'>}, {'command': <'.uno:ObjectMenu'>, 'label': <'_Object'>, 'submenu-action': <'win..uno:ObjectMenu'>, ':submenu': <(uint32 100, uint32 0)>}, {'action': <'win..uno:InsertObjectFloatingFrame'>, 'command': <'.uno:InsertObjectFloatingFrame'>, 'label': <'Float_ing Frame...'>}]), (75, 4, [{'action': <'win..uno:InsertEnvelope'>, 'command': <'.uno:InsertEnvelope'>, 'label': <'En_velope...'>}])],)
$ gdbus call --session --dest :1.194 --object-path /org/libreoffice/window/88080484 --method org.gtk.Actions.Describe .uno:InsertTable
((false, signature '', @av []),)