Luton vent / skylight leak

Hi all. New to the forum and motor home life so still finding our way and after some advise please.
We have taken on the responsibility of running the mother-in-laws 2019 Bourton an have a growing list of snags for the dealer to sort sadly. However whilst on holiday yesterday we had some heavy rain which leaked in from the Luton roof vent / light we think, although we can't really see where from. It soaked our bedding and mattress on the Luton bed so was not a small dribble.

To say we are gutted is an understatement but all will sort.

Has anyone had any similar issue? The van is parked on the level so don't see this to be the issue. I understand its good practice to park slightly front up with a Luton to stop water pooling but the roof vent is obviously at the top of the Luton.
When we picked up the motorhome from the dealer after some work they had to mop up water on the main floor and said water can pool and overcome the air vents required for gas leak reasons. As an engineer I understand the reason for the vents, but seems like I'm getting fobbed off to cover up a poor design. As I'm on holiday I don't have access to ladders to view external. Can anyone offer advise please.
Thanks
James

Good morning and welcome, Jim.

As an engineer you will know that gas is heavier than air, so gas vents will not be at roof level!

There is ventilation around the Heki roof hatches but there is no way anything should allow water ingress to the extent you describe either in the Luton or on the floor. I'm afraid you have a problem.

All I can think is to try to contact a mobile engineer but I'm not sure how successful that would be. If you tell us the area you're in, someone here may have local knowledge of where to obtain help.

Hi Tinwheeler. Thanks for the reply.
I susspected the sales rep was full of the usual because as you say gas is heavier than air, but just assumed it was a regulatory requirement to do with allowing air to circulate and purge any gas leaks out in the event of an issue. Obviously also for general ventilation. 
I certainly interested to know if other have had similar issues. 
Hopefully we can get through the rest of the holiday leak free and I can get up to take a look properly on our return.

Hi Roopert.
Thanks for the reply, and all makes sense. So if we are having water leak in with the van level we either have a faulty vent or a vent not fit for purpose. Motor home is going in for a service soon so will take a look externally myself before it goes in, so I have more info to get it sorted. I get the impression from my last visit they will try and fob us off, but will let's hope I'm mistaken.
I'm guess there are not many manufacturers of the roof vent / light units though.