This rogue entry, which does not start anything and can't be removed, appeared on most of the accounts across all of our three different machines. If you drag the entry to the desktop, it seems that underneath the "ms-resource:AppName/Text" it is pointing at Microsoft.Windows.HolographicFirstRun which is not listed anywhere else (Settings/Applications) and even through PowerShell Get-AppXPackage.
It would appear this is something that was uninstalled but left the entries which the (new Start Menu in 1903) All Apps picks up.
I have found no way to delete this rogue entry - and searching for this shows plenty of examples of the problem, and STILL no resolutions.
I don't have the time (at least a week) to rebuild the machines, nor the time to try to recreate all of the users across them - which is prone to too many errors in doing this (the machines variously have complex set of uses including gaming, video/photo editing, VR and music production).
Surely it is not beyond the wit of Microsoft (or even a third party) to provide a fix for this - or a generic tool to allow experienced users to clean-up entries from All Apps menu (or a FixIt tool to clear these sorts of issues automatically) when these sorts of corruptions occur, which do seem to be too many times (unfortunately).