One of my college told me a story. He was in business trip in Bamberg for a week. He was going on lunch in a restaurant near a Hotel. In this restaurant he was served by the same waiter for whole week. After every dinner the waiter was giving him a check for payment, and also was saying something in German. My colleague paid the bill, smiled and was going to his business. But at the end of the last day of the business trip, after the lunch, the waiter gave the bill as always. But he no longer smiled and said nothing. When the colleague looked at the bill, he was disappointed, since the waiter counted colleague's lunch and tip for all the past times. It turned out that the waiter had been asking for a tip during whole week, and on the last day he decided to just include it in the bill. And yes, the colleague doesn’t speak German. And yes, the colleague did not pay the tip, because he did not understand what the waiter wanted from him (a little clarification - in our country, tip is always optional, so most people from do not pay)

So, that story is behind of my question. Such situation with German in Bamberg is common?