HD vs SD night vision vs regular bitrate

OKay. So… ONE of three of my cams has an issue. SD bitrate hovers 60-80 KB/s both night vision off and on. HD, on the other hand, runs 90-110 KB/s with night vision on, about 15-30 KB/s without, and is VERY glitch, blocky, and the motion box is a mess. Can anyone help? I’ve searched and searched to find dead ends everywhere. No solutions I’ve seen.

It world appear, after a single short test, that the newest firmware update has fixed it.