@Charlottetaylor   RE: The dropdown menu used to allow me to select “Credit Card”, but now, it only shows “Other Current Liability” options, such as Payroll Liabilities. 

This is the key bit if info that reveals what is wrong. For some reason, your credit card provider has written the file incorrectly and is writing it not as a credit card file but as credit line account, like a loan you've taken out. While a credit card balance is sort of a loan, that change will cause only liability accounts to appear as an option when you try to import the *.QBO file.

You can verify this is the case by opening the QBO file in Notepad or any word processor

If you search the file and you see "<ACCTTYPE>CREDITLINE", then it is the wrong type of file for a credit card.

If that's the case, you'll need to convince your credit card provider to create the correct file for a credit card.

If they won't, you can use a tool that will transform the credit line file to a credit card file, like our BRC OFX Cleaner  and then import the file into QuickBooks.