I believe I understand from one related answer that the Charge 5 is not capable of showing or tracking SPO2, except one data point during sleep tracking. Could that be right? The claim that it measured oxygenation was a major reason I bought it.
In any case, it has not recorded an SPO2 for either of the two nights since I bought it, so another of its claimed benefits (sleep quality / apnea detection) cannot be realized.
Perhaps I misunderstand the manual or need to activate something?