Mounted Chain Lightning bug?

Bug Name:

Mounted Chain Lightning bug?​

Bug Description:

Whenever I use Chain lightning on horseback while sidestepping or doing pretty much anything else on my horse, the animation seems to work but it's not dealing damage, though I should be one-shotting the mobs at my level and ap/acc, instead it takes a many repeated attempts to actually kill anything, especially at hexe sanctuary, not even on the shield skeletons.​

How to reproduce/proof:

Attempt to use Chain lightning while side-stepping on horseback at Hexe Sanctuary on Wizard​

 

Yeah that is an issue I think even on Retail (official version), you deal about 2-10 times LESS damage when fighting from horseback and I have NO idea why this is, apparently your horse consumes some of the energy your character is using to attack the mobs

 

Its not a bug, game mechanic u have less dmg from horse cuz u less concentrated.

 

Oh I had no idea, but thanks for the answer

Is there anyway to tweak this damage decrease and the "to hit" modifier?