The Connection Attempt Timed out

After disabling the Timeout in the Expert 'Idle Timeout' on the Win10 RealVNC Server and with the Android RealVNC client working for a week plus without issue, Android client now showing "The Connection Attempt Timed out".   I have substituted Win11 RealVNC Client for testing purposes and it connected without issue.  There seemed to be error Logs on Win10 RealVNC Server without time stamps, but have included them in  trailing.  This OT network by design, has no internet connection for Win10 RealVNC Server.  Could this be rescinding the license & connection?   Early searches on RealVNC seemed to indicate that a one time internet connection was required upon first licensing, which I performed.

But now I'm seeing the error message way at bottom trailing.  Could this be the issue?

No Internet access on OT Win10 RealVNC Server network is hard requirement.  If internet is the issue, 

If lack of internet connection is issue, how often will this reconnect need to be performed to re-establish connection? and is there a work around?...or is RealVNC not a fit for use case? 

Just retried restoring internet connection to server and testing to see if Android client will now connect.
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Warning
Temporarily disconnected from RealVNC services
A networking error has prevented RealVNC Server from contacting RealVNC services.
RealVNC Server will reconnect to RealVNC services as soon as network connectivity is regained. If this problem persists, re-register RealVNC Server or contact RealVNC technical support.
Refresh RealVNC Services.