Hi. I'm sorry to answer late, but I was out for a few days. It looks like this new version changed something. Repetier-server is responding much longer. It looks to me that it stops just when I'm changing back to Repetier-Server tab. I see a new socket in debug tools. But the problem continues.
So the prolonged timeout still does not help here as it sounds which is strange. On my imac it is working. What do you have - imac or laptop? Maybe laptops are more severe here.
I have reduced reconnects to only when tab is active which is why you see only one update.
edited November 2019
You already send a video. There it looked like the data we get via websocket on reconnect was missing. I remember the uuid /server key were missing in that video.
What might be of interest would be the content of the new websocket connection to check if it is sending the correct data. Since these are missing that would at least explain the error. You find it in network tab in debugger if you enter socket in filter. Last one as you already know. In preview you see the data.