Bouncing mobs...?

[Axlrose]

While wandering (and dying) in Swamp of No Hope, my monk will occasionally get attacked by mobs that appear to me to be bouncing up and down (not the faster paced leaping frogloks). As these monsters bash me, I attempt to attack them but get the constant message that these monsters are too far away and get closer. Yet no matter how I attempt to move near where I think these mobs should be, they continue to hit me and I never get to touch them. At least my feign death worked to fend one mob off. But a previous incidence, feign death became permanent death.

This issue seems to come and go, but I wonder if there is anything happening between the game server and me?

Thanks!