Hi, @AccountantLex. I appreciate you for getting back. Let me share additional insights about the troubleshooting steps provided.
I appreciate you for performing the verify and rebuild tool to isolate the issue. Running it fixes the commonly known data issues within your company file that may cause the behavior you're getting when copying and pasting multiple entries into QuickBooks from Excel.
Since you don't see any errors in your file after the process, I'd recommend opening your QuickBooks Desktop (QBDT) file as a master admin to avoid user restrictions. Once opened, try to paste your entries again. I'm adding this article as your reference: Add and edit multiple customers, vendors, and items.
If you're getting the same result, you can proceed with the succeeding solutions provided by JamaicaA above. You can also repair QuickBooks if needed.
Let me know if you have other questions while adding multiple list entries in QBDT. I'm always here to help. Keep safe!
Thank you for the help Angelyn_T.
I think I found the issue!
Its quite silly, but I was copying from an Excel file located on my local machine onto the QB file which is located on a remote desktop. I have no clue why it would only copy one cell but there it is.
I saved the Excel file onto the remote desktop as well (I couldn't do that previously as I wasn't admin and had to ask for the permissions first) and copied and pasted and voila :-)