If you are not "self-hosting", you can skip reading this page.
This is happening because the browser can only open 6 simultaneous connections to the same server.
Some pages in ogame open 5 connections at the same time (fleet page), and the bot opens at least 1 for the websocket.
So if another tab is open, the maximum connections is reached, and the browser refuses to load.
Go to the admin section, settings.
Enable Start https web server
Restart the application
Then open the browser at https://localhost:8081
And you should not longer have issues with the browser loading forever
Get and use firefox https://www.mozilla.org/en-US/firefox/
Open a new tab and go to about:config
Search for network.http.max-persistent-connections-per-server
and put 20
instead of the default 6
And that will solve the browser not loading
Go to your admin section, and toggle on the "reverse tunnel"
Then when you use https://<your-username>.me.ogame.ninja
you should no longer have the browser loading forever issue.
That being said, it should much slower than Solution 1