iPad Calendar scheduled events disappear & reappear

Hello. I upgraded to an ipad pro from an ipadAir a few days ago. My Calendar app is behaving erratically as follows. While in week view, as I scroll forward to future weeks, some of the scheduled events disappear (all day events stay put). Often they will reappear when I scroll backwards. Alternatively, they will reappear if I tap day or month view and then go back to week view. I don’t see any discernible pattern with the disappearing events, although they seem to disappear in clusters (eg, 3-4 consecutive days events missing).

I had already upgraded to iOS 11 while I had the iPad Air and did not have this problem. I don’t see this problem on the calendar on my iMac. However, I just checked my iPhone, and SAME issue. (I don’t typically use the calendar app on my iPhone)

I spent nearly 2 hours with on the phone with Apple Support, ultimately removing all of the software on my iPad Pro and then reinstalling via iTunes directly from the Apple servers. This did NOT fix the issue. Ahhhh. I’m hoping someone from the Apple community can correct this problem.

Thank you!