Note is stalling and mic is cutting off for a second randomly

I got the note from a lad at college and all seems well apart from a few little things.

As the title says, the phone seems to stall every now and then, making the screen unusable for a second or two, the mic cuts off for a second or two in a call and also the pen hover marker is offset.

Does anyone think a software reinstall would fix the problems I have stated?

If not can anyone suggest a method which would get rid of my problems?

Thanks very much :)

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