TVS unintentionally shorting on USB?
It could be the wrong chip mounted.

It could also be that Maxim as they sometimes do, decided to make an updated version with through-signal connection, with maybe another letter following it and this caused this behaviour.

Many manufacturers who make a TVS chip like this also make one with that connection you measured intentionally, so that you can have the signal go in one side and come out another and have extra freedom to wire up ground and pour it underneath for better shielding/characteristic-coupling.

This is half-similar to "mounting the wrong chip", but with the caveat that it's closer to "small mistakes can happen". It is the reason that generally "NC" pins are advised to be kept "NC" at all levels - You don't want to "inherit" ownership of this mistake if you can prevent it.