It’s always possible! I also suspect that the destination of your B-channel TRS could be part of the puzzle. Could it be running to an unbalanced jack which bridges the ring and tip of the TRS cable?
For troubleshooting, you might consider trying an insert cable. This will split the balanced TRS signal into it’s positive and negative components on individual TS cables. Then you can try plugging each into your destination and you should perceive identical (but phase shifted) results between them. If one of the two TS cables doesn’t carry a signal, then you probably have some hardware issues with the RIP.
Multimeters and oscilloscopes are also invaluable tools for troubleshooting 