A mystery that needs to be solved

Here is the back of my Sony A7 mark ii camera. Whenever the screen is on, there is a blue oblong in the centre. This shows up best on the black screen and this is the image I have sent to Sony today. When I'm using Live View or reviewing images, the blue is paler but makes everything look over exposed.

Ahmed, on the support line, said that people have complained about a red patch but not a blue one! He asked me to reset the camera which I did. Now I need to reset the custom buttons.....

The camera takes perfectly good images. This happens with all lenses.

I fear that Sony will want the camera for repair (again) and I'm going away in 4 weeks time, not to mention the Christmas break looming. Ho hum.

Any ideas - or even a solution - are very welcome.

It has been very cold today but we still have no snow. I took Mum to Hexham General for a chest x-ray to follow up the one she had 5 weeks ago. They are looking to see if the x-ray changes have gone away.
 
The plumber has been to have  yet another go to stop the whistling we have in the central heating radiators. I fear without success. He had been busy with a frozen boiler - the oil pipes had frozen. Now that is serious.

Off to Tynedale Photo Group tonight.