When using lightning flash with burning speed, lightning flash simply does not activate around 1/3rd the time when I have Fast Cast Ground Targeting enabled. I press the ability successfully, I see the green circle on the ground, and I let go of the lightning flash ability key in the middle of burning speed. Lightning flash does not trigger, does not go on CD, and I do not get teleported. This only happens around 1/3rd of the time; the other times, it triggers successfully, as expected.
This happens at other occasions too, but most often when I’m trying to combo it with burning speed. It’s quite frustrating. This appears to be a bug with the fast cast ground targeting. I’ve gone back to normal ground targeting until it’s fixed.