Nova Air C refresh bug after firmware update

I updated my Nova Air C to the latest firmware last week and afterwards the top half of the screen doesn't display correctly on all but Regal and HD refresh modes. It'll either display nothing at all or whatever is at the centre of the screen will be shown repeatedly in the top half of the screen. On Regal and HD modes if I turn a page by swiping I'll get the same effect on the new page until the screen refreshes, but it doesn't happen if I press to turn pages. I can still use the device but not do anything that requires fast refresh. It seems to be a display issue as I can still press where icons should be and it'll load the corresponding program. Any help would be appreciated.