Gmail not updating "read" status on mobile devices today?

[Cleargrey]

This is what seems to be happening to me today. I have a G. Nex (4.2.1), Nexus 4 (4.2.2) and a Nexus 7 (4.2.2). When I get an email on any of my linked Gmail addresses, it will come through to all three devices, every time, all within about 5 seconds of each other. Perfect. However now, when it's read on one of the devices, the "read" status is not updated on the devices, and they continue to indicate I have email waiting. When I check my email via Chrome from my desktop, it's correctly shown as read. I've left the devices for over 10 hours and they are still not updating the "read" status unless it is the device the email was read on. If I read it first through my desktop, then the read status is updated to my devices.

Is anyone else having this issue?

 

[Cleargrey]

Problem has now been solved, by doing... Nothing. If it was a problem with local servers, then Google has fixed the problem.