Trouble with new AC

I will assume Newmar has used the 3 wall temp probes. Usually the Wall tstat on your model is the Zone 1 temp sensor, but I believe Newmar started to use a separate temp probe like the Zone 2/3 for Zone 1. If so, find that sensor and remove the plastic cover and let the Thermister bulb end hang loose out of the wall hole. IF there is a wire loom clamp over that Thermister bulb, remove it and discard. Then retest your system and let us know if this has eliminated the problem. It will not hurt the fan by this cycling but it is annoying. IF the problem goes away, reinstall the Thermister bulb behind the cover and do NOT use any type clamp over the thermistor bulb end. Doug

PS, IF they are Penguin units, then the main control board was also new each time they replaced the Roof top units as Penguins come with a new control board already installed.

It's ssooo much easier to trouble-shoot this type of system if only each A/C unit was wired totally independent of each other. Yes, each one with its own thermostat(including ON/OFF switch). I modified the system in my Dutch Star back when it was only 4 months old. I had a terrible experience (going from Arizona to New Mexico), and both units failed. Under warranty, I could not find any approved shop that could look at it right away. I was so motivated(under those hot-weather conditions) that I decided to learn how the A/C control system was designed. When I learned that they were not independently wired(both were controlled by the front-unit circuit board) I couldn't believe it. I modified it myself, and never had a control problem since.
In your case, you gotta find a genuine expert in order to find the cause of your problem.

As long as it's only the fan, it's not going to hurt it to cycle on/off. I'm assuming this is with the fan on auto? I'd try putting it on low so it runs all of the time.
Do you have the same Tstat for the rear units? If so I'd switch the two (take pictures of the dip switch settings before changing) and see what happens. If the problem moves to the rear (leave fan on auto) or the front works OK, then you know what's the problem.

During the years I repaired electronics, I found it was very common to see the same issue in many units. So if you have a problem, chances are lots of others have the same failure as well especially if it's with a new unit.
It was actually fairly rare to see something completely different.
So at least in that regard, your not crazy ;)