Mobs should not attack when they break Fear if under 20% health
 

I see this happen all the time and it is not Classic behavior. When you are fear kiting, and the mob breaks fear, they will attack you once and then return to retreating. This is not the way it's supposed to be. Mobs are supposed to continue to attempt to run, they will never attack back under 20% unless there is another faction mob in proximity or are undead or something.

And that is another issue. I see mobs fighting back until 15% all the time. A mob that went a hair under 20% always began to run.

You may have more success if you provide classic evidence. Lots of people here have thought lots of things were wrong, but in fact it was their memory that was wrong, and they were remembering behavior from after classic (or sometimes even from other games!)

I'm not saying that's you, but again, if you want to clearly differentiate yourself from such folks, objective evidence will be a big help.

See https://wiki.project1999.com/Classic_Research for ideas on finding evidence.

Fear kited literally thousands of mobs in Kunark era and this was not the mechanic. Where's the evidence otherwise? My weak evidence of memory > no evidence.

I also see this happen from time to time. Seems like a glitch. Dont recall ever seeing this happen in classic.