Screen touch un responsiveness

I bought a new tab s2 9.7 inch since I opened it i notice that screen touch not responding well when I registered my e mail I touched the letter 3 times on keepboard screen to be typed .. inspite it's new .. some times I have to touch items three touches in screen to work and the system is slow ..it android is nougat 7.0

I rebooted my tab and I still have the problem .. help me please .. should I change my device or it is a software problem (I have gurantee for 2 yrs)