Just to check here - are the computer and Tablet both connected to the Deco's Wifi?  Or is one or other still getting a connection from (or even cabled to) the Virgin Media router / modem?

Have you been able to perform other connectivity test between the two?  And is one able to ping the other? 

Deco does not usually filter in-network connections, except when it quarantines, or blocks an infected device.

Are both of them getting DHCP IP addresses from the Deco?  There have been issues with the Deco changing the LAN IP subnet to resolve to a confilct with the outside (in your case, Virgin Router) network - which makes the problem go away, but leaves staticly configured devices stranded if you don't resolve the actual problem.

Thanks Kevin,

I've read the link in your message and I'm not sure that's what I'm after as that is about port forwarding for traffic between my network and across the internet. My problem is connecting between two devices within my network. Both my computer running calibre and my tablet running claibre companion are on the deco network.

I'll follow up your other suggestion and ask TP-Link support for help.

Ned

Yes - they are both on the deco network.

I tried pinging but could only do it one way. The reason for this is because the laptop with the calibre ebook library (windows 10) is reporting the deco network as a 'public network. I have now set autodiscovery on for public networks (which I didn't want to do and can ping both ways but still not use calibre companion.

Both devices have new IP addresses and calibre is reporting the new IP address and my tablet knows about it.

I wonder if the problem is because the deco network is being reported as a public network. How can I change that?

Yes, if the network is set to Public, Windows will refuse all inbound connections, and you will get exactly the symptoms you describe.  Windows tends to default new networks to Public to be as secure as possible.

Here’s a couple of links to instructions on changing your network type for Windows 10:

https://windowsloop.com/change-network-from-public-to-private-windows-10/

https://www.tenforums.com/tutorials/6815-set-network-location-private-public-windows-10-a.html

hopefully that will fix it.

All sorted - Thanks everybody for your suggestions and help. I think it was a mcafee problem but am uncertain which particular thing I changed sorted it!