Okay - then you best read through some of the hundreds of posts on problem solving OB connections and get in touch with support if that fails, it’s always just worked for me, so I have no resolution strategies to offer besides the obvious hub issue (which you do not have of course, unless your overhub is starved of current from the mac port due to there being too many devices loaded on it … this may not be an issue, the devices only need a few mA, 10 or so iirc)