Hamlet Defense points - is this a bug?

I was doing Golden Bazaar Hamlet Defense today with my LS and I noticed something strange in the DoL and DoH (de)buff points. We had 2 x DoH players spamming NPC attack+ for both runs, but we only got points for 1-3 "Militia Attack Power Increased" (1-3 x 30 points). At the end of the fight (while we were killing Zombie / boss) they also did the defense and regen buffs, but we didn't get any points for those on any of the runs.

The same thing happened with the DoL debuffs: we got points for the "Enemy Attack Lowered" normally, but nothing for poison or sleep. We did, however, get points for using all DoL debuffs during the fight.

These same things happened in all three of the runs we did today.

So is there a bug and we aren't getting the points we should be getting, or are we maybe doing something wrong or have we misunderstood the point system somehow?

I guess you have to "chain" the buff/debuff to get these points (use it while it's still active)
(I think the french version is clearer and says something like "times X buff/debuff has been used in a row", but I usually play in english)

Thank you for your answer Genz! :) That would explain the points, as our DoH were getting the buff up as the old one had just worn off.