Mongos not accessible after reconfiguring replica set to sharded rs

I’ve reconfigured the replica set as a sharded one as best I can tell. And the config server rs is done. I established a mongos as best as I can tell. But I can’t access the mongos again.
running mongos again produces a forked process but doesn’t progress to "child process successfully started…
I’ve tried accessing with
mongo --port 26000 -u “m103-admin” -p “m103-pass” --authenticationDatabase “admin”
from another bash terminal, but no luck. Just says connection failed. Refers to connect@src/mongo/shell/mongo.js:257:13 @(connect):1:6 exception: connect failed.

I would remove the mongos and set up again but don’t know how to do that.