The usual cause for this problem is that you are allied with the ships you're fighting. You do not get build points for fights against allies. It does not matter what alliance levels you offer. You have to cancel the alliance completely using allies drop.

The intention of this rule is to prevent allies from "generating" activity points by capturing ships back and forth.

This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.