Cancellation of trips

Good day

Uber is wonderful service & quite valuable, however there are issues when it comes to their services, more so the drivers. Why is it, that the drivers DM's you as a user, requesting you to provide details of your pickup & drop off. If you do provide this information, they suddenly cancel the trip. Secondly, this is the SECOND time of me raising this issue, why does it take extremely long to find & driver & why do drivers suddenly cancel your trip?

I would like a response from Uber, as this is not a good experience. I am a regular user of this service every week & this happens every week.