When a trigger does not fire, StarCraft tells you nothing. So debugging is mostly a matter of making values visible.
- Print the counter you suspect with Display Text and watch it.
- Remove conditions one at a time to find which one is false.
- Check for Preserve Trigger first; it explains most “it only worked once” reports.
- Check the players list. CurrentPlayer follows whoever owns the trigger.
- Confirm no unit of your counter type exists on the map. If one does, the value climbs on its own.
Put your debug triggers behind their own switch and you can turn them off for release instead of deleting them.