A static template trigger setup to use trigger correlation, results in a unique event per unique AlarmKey, even if duplicate item values are received. (This is good, and expected)

However when an identical LLD trigger is create (expression referencing an LLD item), it results in duplicate events, if the same item value is received multiple times, with duplicate AlarmKey tags.

The items being referenced in the trigger expression are text, syslogs. The trigger looks for stopped, and the recovery looks for started. The AlarmKey tag is extracted from the log message.

I suggest replicating a basic example of this in your test environment, the behaviour will be quite obvious.