I have to confess most of my problems are with Microsoft Software. For years, the Mac versions of Office have been inferior to the Windows versions.
Based on my current issues, which reoccured just this morning (after 1 execution on a fresh worksheet), I'm seriously considering going back to doing VBA on a Windows virtual machine--Windows 7, and the comparable vintage of Excel.
BTW, VBA on Mac Excel 2016 & -19 runs 3 times slower than on the 2011 Mac version. My virtual Windows machine runs excel about the same speed as the 2011 Mac version.
Thanks for the comments.
Jim