Must not be an actual fix then, maybe my co-op maps always had that bug as well. Glad to see you've actually fixed it, though.

Just as an FYI, there is no functional difference between having a trigger owned by a force and having it owned by all the players within the force: SC will treat it the same.

For the record, I did try your trigger before I ever posted this thread since you had the first coop that I had seen.