Watcher's eye - Precision - flask charge on crit?

Watcher's Eye - Precision - Flask charge on crit? How much is this charging The increase seems very low with every crit. Is this mechanic even working properly? I don’t think so. My flasks do get charged, but I can’t sustain them, even on maps filled with monsters.

I have a high critical strike chance (100% with buffs, and around 50% when unbuffed). However, with the Watcher’s Eye mod (Precision: flask charges on crit), my flasks barely load. How is this possible?
I was reading about this bug/issue on reddit, but I didn't believe that. My bad? Is this intended? I've spent a lot of time and resources crafting these flasks, expecting to bypass Mageblood by using a Stygian Vise setup with sustained flasks. But it doesn’t work at all:


The charging is extremely slow. Even on maps with breaches and dense mobs, my flasks don't stay up consistently. How is this happening?

Comparing to these flasks below:

These flasks have much better sustain and charge significantly faster, even with just a 30% chance to gain a charge on crit and watchers eye removed:


Is this mechanic broken? The difference in performance is massive, and it's really frustrating considering the investment I’ve made. Could there be something wrong with how the charges on crit are being calculated or applied?

The flask charge mod on watchers eye is a massive bait for flask sustain. It gives one charge to one flask with a 100ms cooldown. Its really only worthwhile ish for trying to sustain a unique flask with mageblood since the charges only have one flask to go to.

If you are willing to give up a 5th flask slot the balboa keystone from a brutal restraint timeless jewel and a flask wheel should give you near 100% uptime on four flasks.