That’s with an active/repeater cable - for a single passive USB 2.0 cable length is limited to ~5m (source).
From the USB 2.0 specification (section 6.1) high-speed and full-speed cables should have a twisted pair for the signal wires (as @Outland suggested), and also shielding (as @FairweatherIT suggested). Given you have quite a long cable, which most likely has straight wires and no shielding, it’s not too surprising that it’s having signal issues.
This makes it seem like the cable would only need to be quite short - would you be able to describe your setup in some more detail? It seems a little odd to be using SubConn bulkheads and connectors for this unless the setup is going very deep, and given the costs I’d probably expect a connector on one end and a penetrator on the other.
You might want to look into Cobalt Connectors - @damonblue has previously mentioned that they offer USB-compatible bulkheads and cables 