For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Should'n't be cable issue, if machine is recognized ion DFU.
However, always better to test, when in doubt.
Original Apple Thunderbolt 3 cable is 45€ (0.8m).