J
@vs Don't know the details about Chirpstack nor exactly what setup you have, but does Chirpstack show you the downlinks being sent? Does it state in what RX windows they are sent (RX1 or RX2), at which frequency, data rate, and actual time?
In general, you should consider most LoRaWAN traffic to be best effort. It gets there if it gets there whenever it gets there. LoRaWAN is very suitable for non-time-sensitive applications such as metering or reporting. Not so much command-and-control.
Nevertheless, downlinks exist in confirmed flavours exactly like uplinks. Though as downlinks are only sent in response to an uplink, it may take a while for retransmissions to be sent.