Might not be the same issue but there's a quite annoying bug where if you try to import a csv file with just one small error in it, the import screen tells you everything is fine and that the data was imported, but no data actually gets saved. I encountered this when constructing my own csv files, if a trade had no buy amount for example no errors or warnings were raised, and the whole import failed silently.

Makes it very hard to debug what's actually wrong with the csv file.