Touch issue

My fiancee has an ipad air 2 it is quite new at about a month old.

She started getting "stammering" when typing.

This is intermittent problem.

She turned off the repeat keys option in keyboard settings.
It still happened as before.

So she replaced the screen protector but it still sometimes happened.

she then bought a tempered glass protector, but still getting this stammering/key repeating when typing sometimes.

Do you guys think tablet fault or software?
I told her to go make a backup in itunes so i can factory reset then apply the backup see if it fix it.

 

Just to update everyone....

turns out it was the bear grills armored case that was doing it.

been working fine with it off.

 

this is what we bought:

http://store.discoveryuk.com/jivo-technology-bear-grylls-ipad-air-protection-case-1200.html

Do not buy it.
It seems to put pressure on tablet and upset the touch.
Very difficult to get tablet in and out the case.