Since a few weeks, when I use Excel 2016 I am unable to use the formula bar, the scroll bar and I cannot edit cells. The problem is illustrated in the screenshot below: all the areas mentioned are "hatched". Several files are affected by this problem, but not all the files; I do not understand why. Appartently, the problem appears randomly (but frequently!).
I have reinstalled Office today, but this did not solve the problem. I use Windows 10 Professional, which is updated (version 1903). I use an antivirus (Sophos) which is updated as well.