Ipad air2 multitasking gesture fails occasionally

my ipad air2 multitasking gesture fails to work when I start using the "ZOOM" and even change its setting( general>accesibility>zoom>on/off) also the notification and control center fails to work. I tried to turn the multitasking gesture switch to on/off but it does not resolve, so I restart my ipad and it worked. On the 2nd incident it happened again when I try to explore the "ZOOM" settings. Do I need to return my ipad to apple store? Or wait till ios resolve the problem? Thanks in advance 🙂