Siri un-ables

IPhone 7, Intermittent Siri. I go to settings and unable Siri, then able it and it works. After browsing or using the phone for something else, Siri will not work when pressing home. I speak into it and it tells me shes listening. I then go back to settings, Unable it, then able it, then it works for a few minutes and same scenario. I'm about ready to throw a 90 mph fastball with it. Any help?

TIA

Chris