If using the instructions linked above, then you should cut those rows from the original CSV file, and save them in a separate CSV file — these can be imported into Bitwarden as secure notes, but the data conditioning steps are slightly different than what I had described in the instructions for login items. If you would like to import the secure notes, please let me know.
If you are selecting the file format option “Bitwarden (csv)” when importing, then you need to follow the provided instructions exactly, renaming all columns (except “name”), and adding the 3 required additional columns.
This is probably because you didn’t follow the instructions exactly as described.