Are you very short? I wear a Warrior chest rig and battle belt and am only 5'8", and have no issues. The belt sits on my hips and chest rig straps adjusted high enough to be clear.
The vest I have is bigger than my last one, but i'm quite the underweight chap. I've even had to take of the shoulder straps to make sure the chest rig itself doesn't shift about. My height is 5'9". Tried everything possible but still no luck
Your initial post said chest rig not a plate carrier, that does mainly explain the problem. Probably just need one or the other, or different type of PC. Cannot see the eBay link. The PC is supposed to be worn high.
I was thinking of getting a JPC style PC. Issue being with the belt is I have pretty much my impact grenades and pistol mags, my pistol holster also sits through it as well as the dump pouch. So I can't ditch that off the gear.
I looked through the pictures I literally just took (had none available) and I realised it was pouch positioning at the back that was causing the raise.
However concidering i've never ran with a PC before. I'd still like some tips possibly on it. (Friend of mine recommended the current PC)
(Im mainly running all black due to the colouration of my camouflage)