Curl http host to container doesnt work, but over host browser it does

docker Ubuntu container with a web server on it with exposed/published container port 10000

curl -d passive -X PUT something http://172.18.0.2:10000/\!mode/site

wont connect to the ip .> (110) Connection timed out

calling the following over the host Firefox browser it does

http://172.18.0.2:10000/!mode/site

What could be the possible reason for the behavior?