If I copy data from MS Excel (Mac version 16.16) and don’t have the columns sized large enough, I can see errors in what appears in the resulting base table after pasting that data. A simple example is this simple spreadsheet. Copying its cells and pasting into a base file results in this base table. My Libre Office version is Mac 6.0.6.2.
I can avoid this problem by having the MS Excel columns sized large enough or by opening the MS Excel file with Calc and using Calc for the copy.
When I do the paste into a Calc spreadsheet, it appears as if an image of the copied cells is being pasted.
If I do the paste as a special paste with formatted text (RTF) in base I avoid the problem.
If I do the paste as unformatted text into a Calc spreadsheet, then the Calc cells are populated as expected.