Frequency/Channel imbalance. Help

I'm using a Benz-Micro H3 Ebony on a VPI Scout w/JMW 9 Sig arm. Since purchasing this TT I've mounted 2 carts to it and have noticed a frequency/channel imbalance on both carts so much that the center imaging bends to the left channel. Almost if a bandpass of upper freq are louder. It is mostly apparent in the upper range where the throatiness of vocals reside and I don't know what could be the problem. I can't decide if the left channel sounds a bit too harsh giving the impression it's louder assuming the right channel sounds correct or the right channel is missing the upper presence and sounds to soft. I heard it with the previous cart I used a Clearaudio Virtuoso and am now hearing it with the Benz, with new and used vinyl. I'm at my wits end with this because I love the lushness of vinyl and use it as my primary playback source and I'm not interested in upgrading my digital front end right now. I've meticulously checked the leveling of the table, cartridge loading, VTA, VTF, overhang, etc. I thought it may be the anti-skate but over a period of listening since it's broken in I've adjusted it slightly till I've minimised the sibilance distortion in either channel. I've gone through the whole system swapping channels to see if the cables or one of the preamp devices have a problem and I haven't heard a change. The only thing left is to reverse the pin config from the cart to TT outputs to see if it moves from one channel to the other but I wanted to use that as a last resort. This is actually my second time posting this question in the hopes someone has had a similar occurance they've rectified.

Side question: The dealer that sold me the cart also set it up and put the added weight between the cart and tonearm. I've noticed significant low freq excursions. Sounds like the arm resonance is too low. Should I remove the weight to reduce that?