[osullivj]

I'm guessing this is a bug in the MacOS specific GUI layer for Excel 2016 for Mac. If the core calculation engine, which must be shared with Excel for Windows, had a bug like this it would have noticed and fixed long ago. My guess would be that the GUI code to pull the value from the calc graph isn't triggered if the cell isn't in view. All IMHO of course as I'm not personally familiar with Excel's code. I am intimately familiar with the Excel XLL SDK and Open Office Calc's core calc engine though.

[thomasdereyck]

While I'm not as familiar with low-level Excel as you seem to be, I also suspect this is a rendering bug. If you type "=J64" in cell K45, that cell updates correctly with each change, so the calculation seems to be working fine. Doesn't make it less annoying though. Never had this issue in Excel for Mac 2011 BTW.