Turn off Touch ID and see what happensUPDATE:
After all night not touching my phone when I turned it on there was a lag again, however it was not the same as it was on my previous phone. It was less than a second long, not 1-2 seconds. Siri suggestion is off. I'm gonna try to turn on this feature and see whats happening. On my wife's 6S+ I never ever could reproduce the delay, and all features is on on her device....