The Church doesn't like anything to do with drugs, whether weed or khat so that makes sense. People are not perfect in religion though so it also makes sense that they'd stray from the churches teachings. I've never heard of the Church banning coffee though...
and coffee, a
Muslim tradition?

One of the most central parts of Ethiopian/xabashi culture and tradition is our coffee ceremonies and some people even pray while pouring the coffee. Coffee plant was also found in Ethiopia first and it's been with us for a long time since.