Hello,
RDS environment with 3 SH.
Users via published applications (web apps) had the anomaly of not being able to activate the O365 license due to the password request windows not displayed.
With my user in RDP I realized that the start menu was not working and cause this issues.
Like @Paul Allan at the first time after PS command Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$ ($ _. InstallLocation) \ AppXManifest.xml"}
it worked correctly, but only for a few hours.
After countless attempts and backup restores I found these commands:
reg delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\FirewallRules /va /f
reg delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\RestrictedServices\Configurable\System /va /f
reg delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\RestrictedServices\AppIso\FirewallRules /va /f
Especially for the last one you have to be patient, in my case there were thousands of records
Without restart the server after a few minutes the start menu started working again !!!
I hope this commands can work for you too.