First CSV export of Summarized data fails, subsequent attempts work

Just started noticing this today in our Embedded applications.

I open a report and try Export of Summarized Data to CSV.  It fails with this error:

      File couldn't be created

      Sorry, your report can't be exported to csv right now. Please try again later. If the problem continues, contact support.

If I try it again (and again), the export works successfully, as expected.

I repeated this test directly in PBI Service, and the same thing happens.

The initial CSV export fails, then all subsequent CSV exports work for that report session, any visual.

The XLSX Summarized export always works.

This CSV export failure is a problem because of automation we're doing - script crashes because of it.

Anyone else seeing it?  MS, can you replicate?