This seems to be network related - this may be hard to troubleshoot over the community discussion. Some thoughts - Is this a licensed version of Qlik Sense Enterprise? If so you can contact email@example.com. If this is a trial, you should be able to work directly with your account manager and pre-sales engineer.
The error from Chrome is stating that it cannot reach the IP.
So first a few troubleshooting steps:
After the 30 mins, when you receive the error, can you reach the Qlik Sense hub successfully locally using the browser on the same machine that the server is installed on? - IF so - then at least we know all the services are still running. It may be something failing after 30 mins such as a service.
Does this occur only when accessing the server from a client machine in the network? If so then access to this IP address / ports is blocked by firewall or other security software.
(This suggestion - may not work - but worth a try - the error received is usually something different.) Did you add the IP address to the websocket origin white list? This is under the virtual proxies item in the QMC.
Attach all logs found here:
shutdown ALL Qlik Sense services
delete ALL logs and sub-directories in the Engine, Proxy and Repository folders - they will be recreated
(EDIT) - re-start all the services
access the system locally and remotely - note the results
after 30 mins - repeat the above step - note the results
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