There is a federal recall on some Forest River/Dynamax MBS motorhomes equipped with Curt taillight controller.
There are many posts in this and also some in the Sunseeker and Solera sub forums.
Even some folks who had the recall performed and the Curt controller replaced with the Hopkins have had failures.
I have always thought that the failure was water/moisture related, but the FR folks that post here sometimes say it isn't. I have a detailed post
here where I enclosed the controller in a water tight PVC box. No failures in three years, so far.