Iphone 6s+ just went off

[elf69]

I am at work alone a everyone else off.

I was send sms to my fiancee and sent one and put phone in pocket.

Phone made to "pop" sounds through speaker like an sms arrive but the full alert tone not play.

So took phone out pocket and jabbed home button, nothing, again nothing.

Pushed power button and it turned on.

I never turned it off.

I will keep eye on it but bit odd?

I did tun on 2 stage authentication his morning.
Could it b related?