Does the motor only run in one direction? Can you please take some pictures of the electronic speed controllers connected to the motor leads and let me know when you purchased the ROV?
Our previous ESC design was sent to us with single-direction firmware, and we needed to flash them in-house with reversible firmware. There have been some cases where some made it into ROVs without being re-flashed.
Our new ESCs are shipped to us with reversible firmware.