Both lights are deliberately dim. They are meant to be readable in a dark bedroom rather than to light one, so in daylight you may have to look straight at them.
They go dark while you sleep. On machines that write to the card as you sleep, as ResMed’s do, both lights go dark while a therapy session is running and come back on when it ends. Löwenstein and Philips machines only save at the end of the session, so on those the lights stay on all night. That is not a fault either: turn on Sleep Mode, on the uploader’s own page in SleepHQ, and the lights stay off the whole time the uploader is in your machine.