i wasnt sure its a bug, im 100% sure enemies with shields were not affected by hemlock when i played it, thats why i trashed it, id rather play zypher it doesnt care about shields, and i need reliable freeze or otherwise what is the point of hemlock ability if it nearly never works.. 

It's not a bug. When a shield is active, hemlock's daze is blocked by it.

I have a doubt, then why won't Orion (from whom Hemlock's ability was derived) can affect Ares or Sentinel as both abilities have quite similar mechanics? Please pass the Hemlock ability issue to the Dev team, because Hemlock is already usable only in HS or 2v2 Deathmatches and if Hemlock still has trouble in using its ability to kill certain mechs, then Hemlock definitely will die

Orion sort of supposed to break shields its getting shield piercing bonus when applied.. at least slowing enemies with shields would be nice :) but whatever.. i dont think hemlock would be in my top5 even if it had shield piercing

Hemlock isn't supposed to need shield piercing anyways, as Citadel is the only mech to have a reasonably strong shield but it also has resistance to Daze effect and makes it pretty useless. Hemlock's ability should be reliable to some extent so it can be used without having to worry about a 1000 "what if my Daze does not work in this case?" type of questions. 

Already the game has nerfed Hemlock to a level that it cannot perform in fast-paced competitive matches without proper implants for the mech, so it's only limited to HS and 2v2. I'd not go for the latter because HS is much more exciting and provides more rewards. And if I'm supposed to deal with another problems regarding its ability then what's the point of creating Hemlock. All other mechs could be used with minimal ability-related implants, while Hemlock struggles to play like the rest and has to evaluate a hundred possible scenarios for using its Daze ability. That's downright unacceptable