Why can't I switch on my additive touch on my iPhone?

[iMore Question]

My home button has been broken for a while so Iv been using my assitive touch. I was on my messages when my phone kinda glitched on me only showing me a few of contacts. Then I noticed my assitive touch was gone. So I turned off my phone then back on. I Went to my settings to put it back on but now it won't let me switch it back on?

 

[zerog46]

Is it possible for you to do a reboot and not just turn it off?