Process not triggered for ObjectHasExtendedAttribute table

Hi,

I am in version 9.0 and I want to generate a custom process on table ObjectHasExtendedAttribute.

I have used both INSERT/ASSIGN events (although that table is not ticked as M:N for which the guide says that option "Assign by event" only works),

nevertheless none of them trigger the process when I create a new assignment.

Prescript on process:

If (EventName="INSERT") Then
Values("Generate") = True

End If

Also used

If (EventName="ASSIGN") Then
Values("Generate") = True

End If

Gen condition:

Value = CBool(Values("Generate"))

Any ideas? Is this table not supported for non-custom events or am I missing anything?

Is there a workaround apart from putting a custom event and providing a process plan to trigger this when I need it? As I would like it to be an ad-hoc task, not scheduled?

Thanks in advance.