I am having the exact same issue.  I have updated to Quickbooks Desktop Pro Plus 2019 from the 2018 version.  The export to excel was working in October when I did the third quarter taxes, but not anymore.  I had hoped updating to the 2019 version would fix whatever is wrong, but it didn't.  There was an update in December that I think is causing the issue in Quickbooks.  Do you have a solution for this yet?