vSphere Server 6.5 web client - endless session

I have installed vSphere Server 6.5 on Windows Server 2016

I need an endless session. I used this manual: Increasing the VMware vSphere Web Client session timeout period (2040626) | VMware KB

1. In the file C:\ProgramData\VMware\vCenterServer\cfg\vsphere-client\webclient.properties set "session.timeout = 0"

Once a day, the error "vsphere web client session is no longer authenticated"

In what there can be a reason and how to remove this error?

2. For vSphere HTML5 Client, you can not set an infinite session. By setting "session.timeout" = 0 or -1 I get the error "vsphere web client session is no longer authenticated" when trying to log in.

How do I set an infinite session for the HTML5 Client?

thanks for answers