Zabbix, how to fix wrong trigger action?

Question

Zabbix

Good afternoon! Created 2 external checks, added 2 data items. A trigger is created, if the minimum value for N hours of the first data element < the last value of the second element, then the trigger fires.
If the trigger fires, you must send the values ​​of the elements by email.
Created an action to send an email, added there:

{ITEM.LASTVALUE1} меньше последнего {ITEM.LASTVALUE2}

But the correct values ​​​​come through time. The second value always comes in the right one, but the first one (which is taken as the minimum for N hours) is not always accurate. Often a value comes that does not match the trigger, the first value is even greater than the second, so it should not be.
Tell me where to drop?

Answer 1

{ITEM.LASTVALUE1} is less than last {ITEM.LASTVALUE2}

Is that exactly right?
What you describe would be:
ITEM1.min(N*3600)