Photon setup flashing cyan with a "quick red burst" (now orange burst) [Solved]

I have recently experienced the same problem as described in this thread. After ‘reseting’ the keys, my Photon is recognized as ‘online’ in the developer Dashboard, but it is not properly recognized in the Android App or the Web IDE.

I started experiencing this problem with all of my devices: 2x Photons and 1x Core. (although, I don’t spend much time troubleshooting the Core)