Recently happened to me twice in a short span. After I was assigned the driver, the car was just sitting there for ten minutes. Then it suddenly started approaching and it arrived in 5 minutes, there was no traffic.

I believe they were waiting for me to cancel and have me take the penalty, but I was purposefully not giving up this time. Or they just wan to pick and choose their orders and have no way to cancel an unwanted trip.

Another time the driver came and passed me and went to a different location without stopping or answering messages. I was just watching the car get further and further away.