Did you find a fix for this, I have the same problem and a few others too at my site. Showing Summary via Show > Summary works and also the Planner view. Just not timeslots.
Changing resolution does not help, I can install on another PC and it works fine with the same resolution screen. Local mail file or server mail file makes no difference.
Switching to Basic view of the Calendar by holding CTRL and ALT while opening the Calendar works fine. I'm on Windows 10 1703 build. Going to try 1709 to see if that helps or a re-install
I've tried deleting workspace and non of non essential Notes files, cache etc. but I've not traced this issue yet.