Re-manufactured transmission leak from vent

Hi, I was wondering if you have ever encountered the problem my mechanic is going through right now. I needed a new transmission for my vehicle listed above. I decided to go for a re-manufactured one to avoid any headaches. He installed the transmission, and after testing it, it was leaking some oil. He got a hold of the warranty department and they sent another one. He installed the new one, tested it and it was fine. When the oil cooled down it leaked again. He said the leak is coming from the cooling vents. He’s frustrated as well as I am, he said he’s never seen that before. He even reduce the oil in case it came with some oil already in it. He’s planning on calling their tech team to see what is going on. It’s been about a month. Please help.