XPS 8950, lags when typing in Word and Outlook emails

When typing in word or outlook letters sometimes fail to appear or word are not finished. When i try and correct this as if it was my typing mistake the missing letters then appear but sometimes relatively slowly making the attempted correction clumsy. I often have to delete a few words and /or start a sentence again. It is if they are 'whited out'.

Internet search suggest disable graphic acceleration but there is no uncheck box in my edition to disable graphic. acceleration. other suggestion are mother board drivers but my support assist will not load onto my computer and twice been cut off from Dell telephone support whilst explaiing the problem.

I am using office 365 and it is up to date. As far as i can tell windows and other drivers are up to date. Any other suggestions  appreciated?

ps noticed it is not happening on this page I am writing on now.