Export (download) is not working

We have a three-table base for project management: Projects, Tasks, and Time. All three tables are fairly simple. None of them can be successfully exported. I have tried both table export and view export (view is what I really want, but I'm trying both). I have tried both Excel and CSV formats.

About ⅓ of the time, the download simply fails. The rest of the time, the downloaded file is mostly empty with only partial (and often incorrect) columns and column titles. My real goal is to download Time records so I can import them into our billing system, but when that table failed, I tried downloading the other tables, too. They all produce similar results.

(Note: We have a second base where downloads appear to work fine, both from the table and from the view; unfortunately, we don't need to download from that base. The only base:table we need to download is project:time.)