No, nothing is wrong. Basically you have an ac running to beat the heat, and it's on top of and feeding into a 15 foot open box. No doors to close or block the noise.
Others will chime in about "quieter" models/brands of ac, but their not going to make much difference in your unit.
Just one of the downfalls of rv ac units.
Steve & Cheryl + Zoey, and Ziggy, our furry kids.
2012 Forrest River Lexington 283ts
Toad, 2013 Subaru XV Crosstrek