2010 ford edge 3.5 code p0442

I have this edge here, been here a few time with a check engine light and code p0442 small evap leak. They have had it to the ford dealer numerous times and are always told its the gas cap. This vehicle is not capless and its not flex fuel. When It was here for the last oil change they said they just had it at ford and it needed a new gas cap. I checked and the cap had not been replaced, it looked original and in very bad shape. Customer could not tell me if they had been charged for a new one as its a company account. I visually inspected all the hoses that I could find, checked the vent solenoid and removed the canister to see if it was full of mud, which is common around here. I did replace the gas cap, I figured if ford kept saying it, why not, it was only $30. At present I do not have a smoke machine to test the system, and I made the customer aware of that. But what bothers me is they've had it at ford and were repeatedly told the system had been tested and It was always the gas cap. I know a lot of times with the small leak code the gas cap is checked first, and a lot of times it is said to be loose. I have asked if they leave it running while fueling, but was told no. Are they any common rubbing spots on those evap lines that anyone is aware of, or any really common things in this system? I have strong suspicion it has to do with mud somewhere or damage, really which the shop had a smoke machine, I really don't want to take a wild guess and throw a part at it that it doesn't need. If anyone knows anything common please let me know, thanks

https://www.obd-codes.com/p0442 it may just need a new cap or try and put a little Vaseline around the rubber ring in the cap and put it back on, i had the same issue with a locking cap on my 08 focus my check eng. light would come on or the gas cap light would come on or both but after i removed the locking one and put the stock non-locking one on it was fine never had another issue except the transmission grenaded and the head gasket let loose at 55000km not nice after the warranty ran out