Unable to save changes to maintenance schedule, needing to allocate 40 minutes to the pre-maintenance task

Question

I wanted to change a maintenance schedule in the Azure portal, but there is this message and I can not save my changes.

You have a pre maintenance task configured which will not get triggered in the upcoming scheduled run. Please ensure to allocate at least 40 minutes for the pre maintenance task to execute before the maintenance schedule run.

My Maintenace runs every 6 hours and the window is 2 hours.

I do have events set with this Maintenance Configuration, listening to Microsoft.Maintenance.PreMaintenanceEvent and Microsoft.Maintenance.PostMaintenanceEvent. My events are Azure Functions that will start/stop all of the Session Hosts in a host pool.

Where and what do I update to allocate the 40 minutes ?