Yeah, all the time, even zooming in and out of the window. Its abysmal when you think theres a £4000 machine powering this. Maybe its Office 365 thats the issue, I ****ing hope so.
You can try turning off 'check grammar as I type' it helped me out a lot, for me, grammar isn't as important whilst I'm typing as spelling is so I can deal with that, just have to remember to spellcheck before you send something out.