Impossibile to connect from remote

Roon Server Machine

Windows 10 on Lenovo PC.

Networking Gear & Setup Details

Connected Audio Devices

Number of Tracks in Library

Description of Issue

It Is impossibile to connect to server (it’s running) from any remote (Android and IOS). See attached picture. It works up to One week ago.

Best thing to try is to stop the whole internet chain completely.
Power off all involved equipment, server, switches & especially router. Then power up starting with router%, other network components and lastly your roon server.
In many cases this helps.