Help. 6504 Vibe roof leak

[jsk125]

It was a hard winter. I thought all was good, but I found a little water on the floor of the bathroom. Then I was going to make up the bed and found that one corner of the mattress clearly had water damage. And it was slightly moist underneath. And the seam across the ceiling above the bed was loose. Clearly water traveled inside the ceiling

I'm a newbie to roof problems. I'll go up and look. First, what do I look for, anything obvious? Second, what do dealers do and what should I expect from them. It is a 2013 likely out of warranty. I bought it last year.
Any advice welcome.

[Greyhawk]

We had a roof leak on our 6501 but it was more towards the front. Water had dripped from the o/h light and onto the table. The water traveled above the ceiling and down behind the wall to the TV Antenna Booster. The dealer found what looked like a crack in the caulk along the l/s roof seam. The water followed a roof cross brace to the center of the trailer, into the ceiling light and forward from there.
Just look for something that looks like a crack.
The service manager simply took a caulking gun with silicone and spread it over the existing sealer. Then he replaced the antenna booster because it was fried. Problem solved. There was No Charge even though the unit was 2 years old.
You could also buy a can of "Flex Seal Clear" at Walmart and coat the entire area around the vent. I bought a can for myself, just in case, but I haven't needed to use it.