I think your problem is the fact you have a combination device, Modular devices are very nice in that if ONE MODULE fails you can always use the other one and sometimes, It works that way.
Why not go with a generic transfer switch and and put a progressive dynamics RV Surge Guard (power monitor) in front of it?
I prefer the portable types as they are easier to bypass manually and to remove for repair should they need it, To convert a portable to an "installed" use a Hughes Autoformer Install Kit (or make one up yourself)
If you like, put an autoformer in front of it, (That is how I"d do it)
Home is where I park it!