Not German. I mean that. Any black tea you drink in Germany just doesn't mix right with milk. The colour goes grayish and you taste more the milk than the tea.
English black tea mixes impressively well with milk. Breakfast Tea, Yorkshire Blend, hell, even Earl Grey -- the colour goes a deep vibrant brown and the tea taste and effect is intensified.
It could be the water. I don't think it is, as I can't believe that UK water is so drastically different than what's going on in Germany, but it could be.
I described common English brands/types that mix well with milk. In the UK, when you say "tea" it's immediately understood that you're referring to black tee.
In Germany, "tea" is something else. Tea could mean fruit or herbs or black, it's all on the same level there. Black tea is just another herb tee somehow to them