@reggiehg Please send the calibration videos to leila@robolink.com. For the calibration, the remote should be off. If you are still having trouble you can go ahead and check if the button is damaged or missing by carefully removing the top half of the chassis. If you do this, remove the motors and guards first. Could you also send me the file for the IR sensor code that isn't working?
For pairing multiple drones, pair one at a time using CoDrone.pair(Nearest). Label each CoDrone/controller pair with either a number, sticker, or color so that you know which are paired. The next time you want to connect, grab the same CoDrone/controller pair and make sure to use CoDrone.pair() with no parameters. This will ensure the controller only pairs to the drone it most recently paired to.