I just did some testing and the appearance is different on my iPhone 7 than it is on my 10R. On my 10R the dictate button is there on the bottom right side of the screen. However there is no dictate button on the 7 while flick type is the active keyboard. On the 10R, a double tap of the next keyboard button will cycle through all of my keyboards. However on the 7, I have to double tap and hold the next keyboard button and slide my finger up the side of the screen. As I make my way to the top it will announce different keyboards. So you just release your finger when you're on the one you want. So you want to try double tapping and holding the next keyboard button and sliding up to get the one you want to be active. But the next keyboard button is not there on the 7 when flick type is active. So I do a slide up to have flick type advance to the next keyboard.