Leak from overcab rooflight,

We have a 2011 Cotswold which has a overcab fixed rooflight. When we were in Spain in Feb/march we has a sigificant leak from the top corner onto the driver seat. The water dripped enough to be captured on video and during this particular rainstorm we needed a pan underneath to catch the water,.
My other half managed to seal the area the next day as someone on site has some caravan sealant. When checking back with Marquis as van still under warrenty they couldn't find a reason for the leak ( but didn't remove the sealant). Apparently all the vans with this feature only have sealant down the long sides. I am interested to find out out if anyone else has had a similar problem as Marquis haven't come across this before.

Hi Barbara, if you call me tomorrow I can help you but I need a bit of info from you about your motorhome. One thing I need is the build number which should be in your glove box on a sticker. Call me 01332 360222 option 2. Cheers Mark.

I just wanted to publically thank Mark at Motor Home Plus for picking up on my post and asking me to make contact. Although it seems there are no other rooflight problems in the NE he had come across this leak before . He requested the job number and chassis number and next thing I have had a call direct from Autosleeper factory to see if we could go down and they will inspect, repair or replace under warranty.
We have had quite a baptism in our first year of M/H ownership so hoping that it's over now.
So to the other Cotswold owners - it's worth sharing your M/H problems on this forum.

Rooflight leak --
Following a few days of torrential rain showers we also found that we had a rooflight leak (MPK) not a bad leak and a bucket caught the drips until I could sort it.
Today we have had a gloriously sunny day (Cheshire). So I Removed the rooflight from the inside. Close inspection reveals that at each of the 4 mounting points for the handles the plastic is split - so potentially 4 leaks.
As an interim measure all 4 have been blobbed with silicone as a temp;
repair, as we have more rain due tomorrow.
Long term fix will be to replace the dome lid - but the price of them for what is just a piece of plastic is horrifying.
For a normal opaque dome lid only around £40 +.
Start looking at a clear dome and you can double that price.
Price fixing seems evident?
Anyone know where to get MPK domes other than the expensive ones to be found on ebay? Would love to replace it with a clear dome but the price is prohibitive. Anyone else got thoughts on this?