Hi @Brom,
For the Single Select field in particular, if the data is not shown in a cell, it will not be imported.
Meaning, if you have a single select field in excel where you have 3 options, but all the rows you are importing are only showing 1 option, this is the only option that will get imported.
What I do in such cases is paste all the options in dummy rows before importing then delete them in Airtable.
BR,
Mo