I have a 2018 Z19 with dual axle trailer with surge brakes. I've read where some of the trailers will release the brakes when you put it in reverse. Mine doesn't do that and I have to put the pin in the tongue. I've looked at the manual and can't find whether or not my trailer is supposed to do that. How do I know if mine has the option, and if so, what should I check to troubleshoot?