Cannot connect to mongos
mongos for “MongoDB Shard,” is a routing service for MongoDB shard configurations that processes queries from the application layer, and determines the location of this data in the sharded cluster, in order to complete these operations. From the perspective of the application, a mongos instance behaves identically to any other MongoDB instance.

As you have mention here mongos.conf file 

 net:
      port: xxxxx
      bindIp: 0.0.0.0

   sharding:
      configDB: &lt;configReplSet&gt;/&lt;ip_of_config&gt;:27019


As here i would like to say that here as you are bindIp in mongos.conf file with 0.0.0.0 but in sharding section , you are using  with port number 27019 of any replica set. 

Note : As here I am not able to see any logpath destion in your mongos.conf file. 

As per MongoDB BOL documentation here Starting in MongoDB 3.6, mongos bind to localhost (127.0.0.1) by default.

Did you try with this configuration of your mongos.conf file.

sharding:
  configDB: replicasetname/ipaddress:27019 -- external ip of replica set of any node which port is 27019, as you mention in your code. which must be participate the replication. 
 net:
  bindIp: localhost,ipaddress -- external ip address, if you are using  
  port: xxxxx --port number of mongos, it should be different from replica set node port number
systemLog:
  destination: file
  path: -- log destination of mongos file
  logAppend: true
processManagement:
  fork: true             -- if you are using the fork