Unlike on Mac (have not tested Win yet), the Save file dialogue used on Linux when exporting passwords does not suggest a file name ending in .csv. It still shows the target directory with the *.csv file mask.

It's nothing fatal, but if the user just types the name, saves, and then later tries to open the file, it's not there, until the user realises the *.csv mask. It may be confusing, because the *.csv mask is there during saving as well. For comparison, the "Save page as" function on Linux does add the .html extension to the suggested filename.