We use a URL like yours to access our Enterprise Hub. At no point does it display any of the ports in the URL as I navigate around apps and sheets.
I suspect this is controlled in your DNS and possibly in the White List of your Virtual Proxy in the QMC. But not exactly sure.
Maybe you could provide more specifics on how you are setup.
Let me show you the flow:
I type in my qlik sense hub url and then i press search or enter:
it change to this URL, type in username and password, press enter
it changes back to this URL.
MY problem is.... in the step 2 - how to hide the port number? or how to configure it doest show STEP number 2? just direct from step 1 to step 3?