Fix for this issue is now available in the latest update of InDesign 2021 – that is, InDesign 16.2.1
In the Creative Cloud Desktop application, click on the Updates section on the left. You should be able to see the Update available for InDesign. Please update your InDesign application to this version to try out the fix.
Let us know in the comments section if you still face this problem.
Adobe InDesign Team
An error occurred while saving the commentEagle-Eye commented
....now instead, I get some silly jagged edges in my JPEG file (when I zoom in)....even at 300ppi or 600 ppi. I did not have ANY Export issues until I JUST recently upgraded to Version 16.2.1.