Can't connect to mongos but connect to single shard is working

[zelanium]

Hi team,
i have mongo cluster on kebernetes and have the some problem on connection to mongos.
My SVC on cluster:

mongos-0       NodePort    10.110.92.202   27017:32116/TCP 
sh-0-0           NodePort    10.100.129.4     27017:31029/TCP
sh-1-0           NodePort    10.96.171.33     27017:31030/TCP
sh-2-0           NodePort    10.108.91.104   27017:31031/TCP

Connection to mongos
mongo --host 192.168.12.18 --port 32116 -u admin -p pass
it's work, but when i run test for mongos i get this error:

python3 benchrun.py -f testcases/* -t 125 --includeFilter insert update --includeFilter core --trialTime 100 --host 192.168.12.18 --port 32116 -u admin -p pass -c 10 -m 5 --printArgs true

Finished Testing. Error: Expecting value: line 1 column 1 (char 0)
and skipping test

If i run test to shard for example
python3 benchrun.py -f testcases/* -t 125 --includeFilter insert update --includeFilter core --trialTime 100 --host 192.168.12.18 --port 31029 -u admin -p pass -c 10 -m 5 --printArgs true
it's work. Can you tell me what the problem is?