Immoral Feral Primate

I just went through The Matlan Waterways in act 3 and had an immortal Feral Primate hunt me about 75% of the map. There were no hp bar for it and I could not target or damage it in any way.
It could target me and my minons with actual damage. Killed my minions several times and it wasn't easy to get a town portal going when a small primate disrupted the casting.

I don't know what happened for it to not be targetable, going back to town didn't help.

I too have encountered this angry, invincible ape (Feral Primate) in the water ways. It also targeted minions. I have linked a picture of the little annoyance and circled it. I too could not target it or cursor over to find out what it was. I tried resetting it by going back to town but that didn't work.

[https://imgur.com/a/bSiDu3c]

Same here as mentioned above

Same thing, at first it was funny but this thing actually does damage and it almost killed me)