frenzied ghoul issue?

[Sponge]

14 hours non stop at frenzied, killing all 3 spawns soon as they come up, meaning I killed roughly 30 of each spawn point.

Saw frenzied 4 times at the left (west) spawn point. The middle and right spawn point he never spawned at. I find it hard to believe that there is no issue and he just simply did not spawn at middle or right after 30 kills at each.

Can anyone else confirm in the past few days seeing frenzied ONLY at left spawn point? Considering making a bug post.