Blizzard has turned off the Reforged Version Update request for version 1.31.1

[AshtonLee]

This only happens with version 1.31.1.12173. Lower versions like 1.31.1.12163 or 1.30.4 will still ask for updated Reforged

Spoiler

The battle.net button and the gateway button next to it will be disabled. Other functions still work normally. VD Lan, Single player

 

[deepstrasz]

Weird, the latest 1.31 version for me was

Spoiler

Are you sure yours isn't hacked or modded, especially considering that custom look?

 

[pyf]

@deepstrasz: His is labelled as being a PTR one, built one day after your version

 

[deepstrasz]

His is labelled as being a PTR one, released one day after your version

In that case, that might be the reason. PTR are temporary installments, unstable and not meant for long use.

 

[Ravager16829]

This only happens with version 1.31.1.12173. Lower versions like 1.31.1.12163 or 1.30.4 will still ask for updated Reforged

This problem is still occurred for me on both 1.31 and 1.30.4. When I start the game, there is no update notification for Reforged.
But check the post below for the main reason:

It's better that that Battle.net is disabled because you won't accidentally update to 1.32 which defeats the purpose of these backup files, and the Bonjour installation message is fully unconnected to the Battle.net - you should install Bonjour because that's just the system 1.30+ uses for Local Area Network games list.

It also occurs if you added the game executable to Windows Firewall.
Sometimes, clicking on "Local Area Network" will redirect you to Bonjour and make the Battle.net button active (and so does the update notification).
Talking about the picture you uploaded, are you sure the game's background screen is modified with 3rd party tools?