Small Bug in 5D3 Firmware 1.2.1 - LCD Brightness Adjustment doesn't work properly

[HDCamTeam]

After updating the 5D Mark 3 to firmware 1.2.1 we noticed that there's a small bug:

- The LCD Brightness function does not work properly when the HDMI is set to "Mirroring".

If you change LCD brightness from "Auto" to "Manual" or vice-versa, and try to change the brightness level it doesn't work properly.

PLEASE FORUM MODERATORS: check this phenomenon and forward this report to Canon for further fix.

Thank you very much in advance.

[HDCamTeam]

It seems to happen when using external monitor and "Mirroring" is enabled.

We'll do some more tests to fully confirm

If someone else has also noticed this, please post details.

Thanks!