So many HT and Byregots fails...

[Silverbane]

No there is definitely something that CHANGED behind the scenes with Hasty Touch + Steady Hand II.
I've found in Heavensward (3.0) that if you're leveling a Crafting Class (before 60), and/or don't have high enough gear, there is a high tendency for Hasty Touches (buffed by SHII) to fail FAR MORE OFTEN than the claimed "80% Success."

Unless you have carefully counted the success rate of a few hundred Hasty Touches (HTs), you cannot say that with any reliability.
Do something like was done in this thread on G/E procs, and report the numbers back.

People typically remember the unusual occurrences better, and therefore often over-estimate how often the unusual occurrence occurs. Only by carefully keeping track can this issue be eliminated, and only by counting several hundred potential occurrences of the event.

I haven't kept track of HTs fails myself, but I've had enough synths where all 11 HTs succeeded to be skeptical of claims that it is not working as advertised. The devs have no motive to lie about it, and I believe it unlikely to have crept in as a bug at this point.