Fleeing and Merging

Have 2 zombie army. First army is idle. Second army comes to me. I use Hound Master’s ability on first army.

After 1 hour, they merged into one army and come to me.

After 1 hour(they touch a waypoint within the time), they run away from me.

Why they need touch a waypoint before fleeing? Is it a BUG?

Well, from what I can see the merged army took over the movement details from the second army, so it kept moving towards you (due to the way merging works, the first army was destroyed and the second just had stuff added to it).
However, merging apparently doesn’t trigger any abilities/CC status effects or the like.

Then the unit hit the next waypoint, at which point it checked for any afflicted stuff (presumably this was put in as a backup specifically for these kinds of situations). It saw that it had a “new” status effect which forced movement (which it took over when merging), and changed its movement orders accordingly.

Yeah, this looks like a bug to me. I will log a bug and see if I can look into it in a few days. Thanks very much for taking the time to let us know @wifish