Docker swarm's routing mesh isn't working

Hello All,

I’ve set up Docker Swarm on 3 Oracle Linux 9 VMs (linux1, linux2, linux3) hosted on Oracle Cloud. I deployed a stack with Apache and Tomcat. The leader node (linux1) is in drain mode, linux2 is a manager, and linux3 is a worker.

I can access Apache and Tomcat using linux2 and linux3’s public IPs, but I get a 504 Gateway Timeout error when using linux1’s public IP. I also get the same error on linux3 if I scale down my stack service, and the same for linux2. So, it seems the routing mesh is not functioning properly.

Error Message:
Gateway Timeout Server error - server xxx.xx.xxx.xxx is unreachable at this moment.

Please retry the request or contact your administrator.

Any help on this would be highly appreciated!