Daas Yochid -Best thing to do is to contact him yourself. If you want me to guess, I’d say maybe this is the reason of the alert!
I personally never drink coffee. I once had a cup of coffee from a starbucks in one of these service areas because I was really tired. I doubt there was a problem because it looked like that’s all they served.
I do know that where I live a lot of frum people go to the starbucks and get cofee and cookies. I already posted that the cookies are treif, now there is a Shaila on their coffee.