Romain and his team produced this beta firmware, which I have been authorized to post here, that resolves the issue of LEDs on even during night mode on the RE900XD:...

Just to update on this thread, I've been in contact via mail with a technical support team who were able to reproduce the bug and are actively working on a solution for an upcoming beta firmware....

@Joseph-TP thanks, but I think there is an issue with the RE900XD. I set night mode through the web interface, but only the power led went off, while the WiFi led still stayed on: I don't think this...

@Joseph-TP I don't remember doing anything in the WebGUI before, but maybe I remember wrong.

@terziyski thanks, I was able to set the night mode on the RE900XD following your directions. I find it odd that this particular setting can be found only in the webpage, and only for this model.

@Joseph-TP Problem is, I don't have that option in tether app. This is what I get: