The issue which you are facing is only come when you have updated gitlab or make any change in the gitlab config file. So in that case you need to run the reconfigure and restart command because sometime gitlab start misbehaving.
I request you to run the below command and share the output also.
to reconfigure the gitlab:
to restart the gitlab:
After performing the step 1 perform the step 2:
The output which is share by you seems to be a DNS issue however I request you to post the output of the below command for further investigation.
to check the gitlab environment information(system information):
to check hostname of the machine:
verify hostname of machine:
to check url for gitlab:
cat /etc/gitlab/gitlab.rb | grep external_url
to check gitlab component:
sudo gitlab-ctl status
to check DNS on your machine and the machines you are testing your URL:
nslookup your domain name
to check the route:
traceroute your domain name
to check port is open for GitLab or not:
to check selinux status:
to check any firewall enabled or not:
I hope the above step’s will help you.