about Gain a Flask Charge when you deal a Critical Strike while affected by Precision not work

Regarding the Watcher's Eye pendant mentioning "Gain a Flask Charge when dealing a Critical Strike while affected by Precision," it seems that critical strikes dealt with by arrows triggered by Manaforged Arrows Support are not working. Can someone help me figure out what's going on?
Furthermore, I discovered that if the potion is fully charged and used on a boss while the potion is at full charge, this effect cannot be triggered, allowing the potion's effect to function.