Navigraph keeps losing network connection

This is very annoying! - I am using charts on PC with X-Plane and it keeps losing network connection.

It does this after I have imported a flight from Simbrief and after spending time setting the departure/arrival charts up. Navigraph then goes blank informing me there is no network connection and I have to start again! When I have started and setup again it seems to be OK.

It does not log me out of Navigraph just tells me no network connection. Simlink is up to date too.

This PC has no problem with connection to the network - it is via ethernet and no other app and also X-Plane does not lose connection so Navigraph must have a bug.

Any ideas anyone as I may have to dump Navigraph as I am getting fed up with this.