Voyage v3134rl kitchen sink drain issue

[ChillinOut]

Does anyone have the above model, and does your kitchen sink drain properly? I just took delivery, still in delivery lot, and I am not getting anywhere with dealership or Winnebago. I am a full-timer, and this will be impossible to live with. All other drains work well. Dealership claims it is a design issue. Any input would be welcomed, especially if you have this model (mine is 2020) and your experience with sink drainage.

[Morich]

First thought would be to tell them, they should not be selling RV with design issues that don't let the sink drain correctly! Second would be to tell them I want my money back? Simply having an excuse handy is not the point. Assuming it is draining slowly, I would want somebody to take the trap off and run a snake down it to see if they could get a bunch of debris out of it.
First time I drained the black water on my brand new Thor, I got yellow packing straps! Part of the reason I now drive a Winnebago, at least it looks like they intended to do it better.

[ChillinOut]

Winnie responded this afternoon, and dealership tech just left 30 min ago. Winnie told me it is either p-trap or vent, and someone called dealership. Dealership said pipe had to be cut, routed different etc. During this time I saw owners of new identical unit right near me here in the delivery lot. They showed me their sink working fine, and piping under the sink identical. Then very late this afternoon techs arrive to cut the pipe. I firmly told them absolutely not, the other unit works fine. Check the p-trap and vent. 5 minutes later a faulty vent was found. It's just this small white plastic vent cap screwed on under the sink. They took a vent out of another unit and resolved. Ridiculous they never checked this the other day instead of claiming "design issue".