"After trigger" with a period of time larger or equal to 1000 seconds doesn't work correctly

[PeronistaUniversal]

I'm using Blink example as a test case. If a change the time period from 500 ms to 1000 seconds (as in 'after 1000 s') or a larger value, it triggers in a much shorter period of time. For example, if I set the trigger to 1000 seconds, it triggers after only 17 seconds. And with 1200 seconds, it triggers after 20 seconds. I'm using the code generation settings as it comes, Timer 1 and interval at 100 ms.