Traffic not displaying

[Wrongstuff]

Appreciate any help. I have had a Nuvi 765T for over a year and Traffic has worked fine. I also subscribed to the premium service for 30 quid. Recently I have a problem with traffic not displaying, I get the green light on the lighter socket, but a very intermitent display. Last night I came down from Scotland to Milton Keynes and all the way down the M74 it worked, then went gray and occasionally got the traffic symbol on the display.
It used to be that on start in MK the traffic came on the display and I hardly ever lost it. It could be co-incidence but ever since the firmware upgrade to 3.6 Traffic has been a problem.
According to the 765 I am recieving loads of traffic data.

Any ideas apart from the unit is faulty?

Also appreciate advice how to roll back the firmware to previous setting.
thanks

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!