As I have had the same problem with my 2018 Holiday Rambler I spent quite a lot of time, my back round includes electrical substation maint, my problem narrowed down to the FIREFLY system. On different occasions the firefly would sense low voltage coming from pedestal. I also had an aux surge protector at pedestal, my thought 2 is better than one and that one read proper voltage. Also used a good multi meter to confirm. Read voltage at protector both high side and low side, voltage good. Problem when voltage was a bit low at campground, around 110V the firefly was a bit out of calibration so it would sense lower than 107 and cause the contactor to open. After a few long conversations with firefly and surge guard we were able to determine that this was indeed the cause. So I recalibrated the firefly and haven't had a problem since.
