Have you reported the issue to Microsoft to ask them to have a look?

we have an issue where all our servers with “net.Tcp Port sharing service” gets stopped and disabled after about 6 hours of starting it. i checked event log and nothing like an error but it only says service is stopped and then another event to say it is disabled. there is no log other than this i can look at what is causing this issue. i tried all sort of options but nothing seems to tell me about the source.

can anyone suggest a solution?

Aren’t you a little behind the curve asking about installing a potentially important patch four months after its release?

Yes. You’re out of support if you use that version. CU22 is the latest and that’s what you should be running: https://docs.microsoft.com/en-us/exchange/new-features/build-numbers-and-release-dates?view=exchserver-2019

I believe it was just that they needed some extra time to work on the update.

For now they provided some KB on that topic https://support.microsoft.com/en-us/topic/owa-redirection-doesn-t-work-after-installing-november-2021-security-updates-for-exchange-server-2019-2016-or-2013-9dc8f203-351e-4527-b9b6-794a2c947d44
But not full solution (and working workaround only for ex 2019 and 2016, not 2013).

Put server in mgmt mode, upgrade to CU22, reboot, and test again. Remember to fix your namespaces.