WVD - NLA required for user logins, not admins

HenrikBryne : Can you run Diagnostics to get the exact error message for the user? Similar to this: https://docs.microsoft.com/en-us/azure/virtual-desktop/diagnostics-role-service#filter-diagnostic-activities-by-activity-type

But please run

$activities = Get-RdsDiagnosticActivities -TenantName <tenantName> -ActivityType Connection -Outcome Failure -Detailed

You can then expand $activities to see individual items. If you look at a specific item, you can then expand the Errors property to see the detailed error that might indicate why the connections are failing.