I'm a bit surprised I don't see anyone else with this issue here - since 2 or 3 weeks my display backlight stays on all the time while broadcasting HR, which just kills the battery. I have to set the backlight to 0% manually before broadcasting if I plan to go on a longer bike ride.
Installed FW is 6.30, unfortunately I'm not sure if this problem already existed before the last update.
I have NOT done a reset yet because it is always such a pain in the a** to set everything up again but if no one else can reproduce that I sure will give it a try.