ODK Central webpage failed to show up after successful docker-compose up and all process is up

1. What is the problem? Be very detailed.
I restarted ODK Centrol via "docker-compose stop" and then "docker-compose up -d", all commands have completed successfully. Also "docker-compose ps" shows everything is up and healthy. But when I visited the webpage it said:

This site can’t be reached <site name> took too long to respond.

2. What app or server are you using and on what device and operating system? Include version numbers.
This is ODK Central on Centos 7.

3. What you have you tried to fix the problem?
Tried to restarting the server and odk central.

4. What steps can we take to reproduce the problem?
No idea.

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.
Before "docker-compose stop" and then "docker-compose up -d", the odk web is available.