Firewall Transaction Details | STATUS: FAILED | EVENT : UPDATE "statusmessage": "record exists"

Using Sophos Central Firewall Management to make changes to multiple XGS136 (SFOS 20.0.0 GA-Build222)

The Tasks Queue are failed:
Firewall Transaction Details
ID : 123 | STATUS: FAILED | EVENT : UPDATE
ExampleApplicationFilter (Update app filter policy api)
record exists (503)
{
"response": {
"Entity": "applicationfilterpolicy",
"statusmessage": "record exists",
"status": "503",
"Event": "UPDATE"
}
}

Because the statusmessage is "Record Exists" 
The I have deleted the Application filter: ExampleApplicationFilter

Then I click Retry in Task Queue ID : 123

I get the same FAILED message

When I click: Skip (Ignore this failure) 
The Queue got stuck on the next ID #124 with the same FAILED message.

Is it possible to clear all Task Queues?
Is this a known problem?