The URI you are using is wrong. You are using part old style and part SRV. The DNS name cluster9-rsadq.mongodb.net does not correspond to a host. It correspond to a cluster. It has the following DNS entry:
;; ANSWER SECTION:
cluster0-rsadq.mongodb.net. 59 IN TXT "authSource=admin&replicaSet=Cluster0-shard-0"
So your hosts are:
;; ANSWER SECTION:
_mongodb._tcp.cluster0-rsadq.mongodb.net. 59 IN SRV 0 0 27017 cluster0-shard-00-00-rsadq.mongodb.net.
_mongodb._tcp.cluster0-rsadq.mongodb.net. 59 IN SRV 0 0 27017 cluster0-shard-00-01-rsadq.mongodb.net.
_mongodb._tcp.cluster0-rsadq.mongodb.net. 59 IN SRV 0 0 27017 cluster0-shard-00-02-rsadq.mongodb.net.
To use SRV, remove the port number and use mongodb+srv:// rather than mongodb:// like it was given in the examples.