Need some help ground buzz narrowed down to the tonearm on my Prime

I have been dealing with a hum in my phono chain. I sorted out a ground loop caused by the integrated amp and phono pre being on different circuits. Now I have narrowed the remaining buzzing down to the tonearm and cartridge. I am looking for a little help and some things to try to get rid of the buzz. 
With the phono pre on the buzz gets louder if I touch the tonearm lift or go near any of the wires. If the lemo connector is disconnected from the junction box the buzzing stops altogether. I am not sure how to resolve the issue or what the problem even is. I would appreciate any help you all would be willing to give.
Is the pickup arm and/or turntable grounded? Is so, to what? It's often necessary to ground the arm to the phono preamp. But, not always.