sounds to me as if the azimuth might be wrong. if you have a small bubble level, designed for this, you can put it on the headshell, put the stylus on the lp and check for level. if it's not level, often you can gently try to twist the headshell, while it's in the bayonet mount, that it can be made level. Generally, this works because you don't usually have to move it very far. why didn't it affect the other one you ask, because 1, you changed something in the alignment somehow, 2, the stylus in the other cart was less susceptible to be affected by this azimuth out of balance for whatever the reason, or both or some other reason I haven't considered. Give it a go.
didn't realize you had a proprietary AR until I looked at the pic. sorry. mine is more of an "S" tonearm, bayonet headshell generalization. Have no experience how relevant it is to the AR setup