Second the sensor on the XM5 is known to be flaky. These are about a year old and already acting up.
It’s just a poorly built and poorly designed headset for me. I cannot even count the number of times I don’t notice they are on until the next day and they are dead.
Currently wearing my XM4s and was really confused by the "physical off button" because ... I'm looking at them and they just don't? Where is it? What?
Then I realised that I'm old and, to me, "physical off button" means a sliding switch, a hardware disconnect, etc. (such as exists on my pair of Plantronics BackBeat PRO 2), not a pushbutton that triggers a software power-down (which the XM4s most certainly do have.)
And at least for the Sony my struggle is it’s a multi-function push down button. Maybe a weird gripe but I miss my non off switches. Easy to turn on and off and easy to see the state.