2016 KW W900L electrical issue

Hello! I bought a well cared for 2016 W900L last fall. A couple days ago I started having an issue with the turn signals. Today I had some time to try and figure something out...to no avail.
Left turn signal works fine. Right turn signal is backfeeding through the left fender turn signal and right side trailer marker lights and all the trailer tail and brake lights and makes the dash lights flash. If I turn the marker lights on everything is fine except it still makes the driver side fender turn signal flash. I though maybe the trailer cord was the issue. Replaced with new still does it. Does it with other trailers to...I am thinking ground issue maybe. Not sure where to start looking now...any ideas? Thank you.