When using the "Export Data" function from a table in Power BI Desktop (not the web service), the resulting .csv export is incomplete (missing many rows) if the table has been scrolled to the bottom of the table (and all the data has loaded to the visual table on the report canvas).
This seems counter-intuitive, as I was intentionally scrolling to the bottom to ensure that all data would be exported, but this only results in an incomplete export (consistently, only 378 rows of a 1873 row table will export to .csv in my use case). If I leave the visual table unscrolled/not fully loaded on the report canvas, the entire table is successfully exported.
This appears to be a bug that causes incomplete file exports, and I've experienced it in other datasets as well -- I created a simplified workbook that I am happy to share which illustrates the issue.
The export appears to be correct when exporting from the same table visual in the Power BI service online, so it only appears to affect Power BI Desktop.