but there is no maintenance mode active .. just running in a timeout
thats what the TO means.
they could be updating website services, thus it's timeouting. That isn't that hard to understand.
There is are many vary to add an maintenance mode for it
Usually u have a lot of webservers in a big company, there are always some revere proxies .... THEY can show you a maintenance page when the real webserver is down
cost 5 minutes to configure it with an apache webserver + https cert and then u have it for the rest of the servers life