Tetris Effect Connected: A network error occurred. Please check your internet connection....

Thanks again.

Somewhat reluctant to change the router settings, I decided to dig out my old laptop, installed the Xbox app and tetris app onto it. It worked. Good news as it shows it must be a config issue on the PC itself - the laptop was tested on the same network.

Any other suggestions on modifying settings on the PC itself to get the game working?

Yes, is right there, but what you could also do is to look for a tutorial on how to add those particular ports to your router model. Because every router is a bit different regarding its configurations. But according to the pic you sent, you're in the right place.

Ok, probably, an instability there. I do advise you to try again to reinstall the game Jas, if possible, in another drive on your PC.

Thanks for the suggestion.

I contacted my ISP but they told me they could not do those things for me, and said I need to do this myself. I don't really understand all the settings options so perhaps you can advise.

1. I tested activating the DMZ, putting my PC's IPv4 address into the local host field. That didn't fix it.

2. I reset the PnP. That didn't fix it.

3. To open ports I am confronted with a lot of options and I don't really know what to do. Can you advise which fields I need to edit from this GUI to enter the ports mentioned in your suggestion? I have added a screenshot of the interface.

Thanks again,

Thanks again.

I followed your suggestion of reinstalling the game on a different drive but the issue remains.