I do not know that trailer, but know some lights are controlled from more than 1 switch. I would turn on every light switch through the rv, make sure they are all on. Turn that 1 switch off and see what happens. If all else fails, talk to the service manager at the dealer.
2013 24RKSWE (27ft TT) Cougar 1/2 ton series
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed 3.55 rear end lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.