I would be very surprised if the pressure sensor were the cause of the leak- there are a lot of Bar30s out in the world, and we’ve never seen one or had anyone else have one leak. It is possible, but very unlikely.
The power cables however can be sensitive during potting, and I strongly suspect your leak can be tracked down to there. You can contact us at email@example.com, and we’ll get a replacement to you as well as troubleshoot the pressure sensor if you’re still having problems with it.
To track down a particularity pesky leak, it is possible to do a lot more aggressive vacuum test, leaving the test running overnight or even longer. Air can leak through the other end of the tether, so this needs to be removed and plugged with a rubber stopper. Any vacuum pump will also leak slowly, so a ball valve before the ROV is also needed.