Trouble Importing From Unpacked Dashlane csv s - Incorrect File Format Error Message

Hi! I’m attempting to import from Dashlane so I can dump them.
I exported the csvs in the zipped file format as instructed.
I unpacked the zipped file and, as expected, now have a list of about 6 individual csv files.
Instructions are to import them one-by-one into a Bitwarden vault.
I successfully imported two of the csv files (I think?). I can see SOME of my old password files.
When I attempt to import the other files into Bitwarden, I get the error message that they cannot be imported because they are in an improper file format.
They appear to me to be Excel files, but with a .csv file extension. They all are. As were the two that appeared to work.
I’m not stupid nor a techno-peasant. But I’m stuck.
Thank you in advance for any help you might offer.