I have updated my iPhone 6 Plus to iOS 10 and now when I switch from wifi to cellular I cannot get mobile data without a full reboot. I also have some difficulty maintianing wifi. Any thoughts?

I updatetd my iPhone 6 Plus to iOS 10.0.1 and have networking issuse. My wifi is unstable. I noticed this when I was downloading files overnight and they stopped about halfway but it still showed connected to wifi. I could not access any web pages. When I switch from wifi to cellular it shows a 4g connection but I have no mobile data. If I reboot my phone I can then connect to mobile data networks and view web pages. Any thoughts on what is up as I do not want to reboot my phone everytime I leave a wifi network I am using.