I think the question was answered above.
But I've personally gotten the same question asked numerous times, I tell them to create contacts and they tell me it still doesn't work. So I'll just leave a small "list" of things you should check before programming a radio for monitoring.
1. Get an SDR, a lot of the following issues can be diagnosed before even trying to figure things out.
2. Make sure the system isn't using RAS. RR doesn't list the use of RAS very often. Simply, RAS is a MotoTRBO feature that prevents unauthorized listeners/transmitters using a radio (some chinese radios have "ignore RAS" feature, do your own research!). RAS enabled repeaters (conventional or trunked) will not unmute on your radio (meaning you won't hear anything).
3. Make sure the system isn't trunked, some people mistaken Capacity+ single freq/site trunking as conventional. That can also lead to issues like part of the conversation not receiving (mainly because the TG is on a different timeslot). You could program your radio to monitor the system as a Capacity+ system (using Capacity+ parameters in CPS), however I recommend against doing that for beginners, especially if you aren't sure of what you are doing.
^ These are some of the most basic things you should check before programming the radio for a system. I hope the op is enjoying monitoring the DMR system!