As a follow up. Take a look at the returned CR.
I wouldn't normally even touch anything like this. In fact this turns ON and OFF and keeps OFF but the OFF only happens when the button is released.
Looking at the residue left behind from soldering or whatever in the world happened on the SMD side ... I am surprised this CR even works at all. Anyway a quick cleanup and it works just fine.
Anyway I can't spend my time doing cleanups and debugs of unknown events, this is not how I delivered any board. Normally if the fault was present out of the box then we would have something to talk about. That is why I test everything and ensure faults like you reported do not ship. So I at least expect people to send me a board that is in new or near new condition and not soldered and drenched in flux residue, if there is any claim of a fault.
This is no fault, the CR will be returned.