SQL Server 2022 Always On Dashboard Error Object reference not set to an instance of an object

Today we did an update of our On-Prem SQL Servers from 2019 to 2022. Update worked. Always On Group is also healthy. But when I try to open the Always On Dashboard I get an error stating:

ITLE: Microsoft.SqlServer.Management.HadrTasks

Object reference not set to an instance of an object.

BUTTONS:

OK

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Object reference not set to an instance of an object. (Microsoft.SqlServer.Management.HadrTasks)

Program Location:

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardDataContext.GetAlwaysOnEventFileTargetName(XEStore xeStore)

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardDataContext.LoadXESessionState(XEStore xeStore)

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardDataContext.Load(ServerConnection connection, String groupName, CancellationToken cancel, AlwaysOnPolicyStore policyStore, XEStore xeStore)

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardModel.LoadData(ServerConnection connection, AlwaysOnPolicyStore policyStore, XEStore xeStore)

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardModel.PerformUpdate()

at Microsoft.SqlServer.Management.Hadr.OperationsDashboardModel.Update()

Scripts I tried on Primary gave me:

Scripts on Secondaries gave me:

Does anybody know why the dashboard is throwing this error?

I also checked the state of my Always On Group with SQL Sentry. There it seems everything is fine:

Hoping for your help.

BR Johannes