QFX (Quicken OFX data) files are not OFX files
Access ProperSoft tools at https://www.propersoft.net/
Quicken imports QFX files and does not import OFX files. Quicken set QFX file description as "Quicken OFX data" creating great confusion for its users that believe they need OFX files it import their data. Use ProperSoft tools to convert your CSV files to QFX (Web Connect) format.
00:00 - .ofx and qfx. extensions
00:29 - Quicken OFX data file
01:17 - ProperSoft CSV2QFX converter
This video is to explain the difference between the OFX file and the QFX file. Some confusions, that you may see when you work with the QFX file. OFX file has .ofx extension and QFX file (Web Connect File) has .qfx extension. Quicken marks them, when you install Quicken on your computer, register Doc files as Quicken OFX files. So you can be easily confused, that .qfx file is actually an OFX file, but it is not. QFX file is Quicken Web Connect File, which Quicken calls Quicken OFX data file.
Quicken doesn't import OFX files. It imports only .qfx files. But Quicken calls them Quicken OFX files. So when you use some converters, for example, ProperConvert Converter, and you convert CSV to QFX and you'll get the .qfx file, but you'll see in the file explorer, that it's called Quicken OFX data file, if you have installed Quicken on your computer. Don't be confused by this description here.