That's very common in Prague. Uber in Prague is a disaster. About 5% of my rides are probably ending up with having to pay a cancellation fee for a driver who never showed up. Contacting support to resolve this is pain indeed. Most of the Uber rides in Prague are owned by limited liability companies (s r.o.). I guess there's some kind of an alliance between Uber and those local companies.

Another 5-10% or so of my Uber orders in Prague involve driver coming my way then cancelling after 5-10 minutes in the middle, then another driver picking up, and so on. You could be on a 3rd or 4th driver sometimes. Initially I thought this had something to do with traffic jams, but I am now beginning to doubt this, as it happened in mild traffic and off-peak hours as well. It is impossible to trust if Uber will arrive in 10 minutes, 20 minutes or not at all. An Uber ride to the airport is a lottery sometimes.

Finally, arrival times are usually understated. It can be 7 minutes on display but 15 minutes in reality. And this is mostly in Kosire area, about 15 minutes from the center. Whoever is reading this in Uber should really look into their Prague situation.

That being said, I am using Uber extensively in London as well and never have these issues. I also used it in California and never had issues. Uber in Prague is something else, my friends.