Naim Nova/Sony TV problem

Frustration! I have a Sony TV and my Naim Nova connected to same router. Lately the picture freeze for a second or two and some pixels are missing. If I disconnect my Nova from the router it stops. Nova and TV is also connected via HDMI, I have not tried to disconnect HDMI. It all started a couple of weeks ago.

Any suggestions?

Very strange. Have you tried a restart of the router?

I hope it is solved - restart router and Nova, fingers crossed