Alarm Clock Event Does Not Trigger

The Alarm Clock event context does not seem to work on my Galaxy S9 with Android 8.0. I am using the stock alarm app. My Tasker version is 5.5

I have tried both named and unnamed alarms. Here is one of the test profiles I used:

    Profile: Alarm Event Test
        
        Event: Alarm Clock 
        Label: Test
        
    Enter: 
    A1: Flash 
        Text: Alarm 
        Long: Off 

No toast appears when the alarm goes off.