Why does a freeze trap activate a second time under some circumstances, right when monsters are about to get unfrozen?
Is it % based or can anything be done to always get it?
For years, due to how PSO handles its damage data packets, when the connection latency is high, players' damage can cancel each other if the attacks were dealt close in time. We call this "damage cancel", "dmc" for short.
This bug is particularly frustrating as you might be trying to clear enemy waves efficiently, but your damage was cancelled by weaker attacks and you have to spend much more time clearing the wave, or you might be using risky but powerful weapons (berserk, Dark Flow) and if an enemy did not die as expected, it might kill you.
This bug had a fortunate side effect however. When multiple players were attacking the same frozen enemy, the freeze timer could potentially gets overwritten by the same timer from an earlier time, which causes the enemy to refreeze. This is especially useful in Challenge Mode, where a party could keep certain minibosses frozen for a long time as they keep attacking it.
Two months ago, a fix for this bug was pushed for Ephinea, which greatly alleviated this issue. But the current implementation actually allows you to dmc yourself in certain scenarios, which is most noticeable when you use a mechgun. As a side effect, you can now occasionally refreeze an enemy as well.