When I am at the dock and plugged into shore power I can not receive any AM or FM stations on the radio even if the main A/C panel breakers are off. I thought the problem was the antenna and purchased a VHF FM splitter and ran the connections over the NAV station to avoid any interference. Was still not able to receive anything. As soon as I disconnect shore power however the radio works fine and I can get all the stations. I have an A/C pro monitor for grounds and galvanic isolator and all indications are normal.Any ideas on how to resolve this issue