Full Description not updating with import

Hello
I am having a problem with product full descriptions updating with imports. I tried putting the new code into the Full Description column on the Excel sheet and import. I get a message that it was successful, but when I check it is the same.
I had success when I test tried clearing the code out of one cell for the Full description, importing, then adding the new code into the cell and importing. But this will not work for multiple lines. When I clear the code on multiple products and the import states successful, the old code remains.
Can someone please help me figure this out as I have over 500 sku and two sites to update.

Thank you

Hello, I just update one product with import functionality in nop 4.0.

It is working fine as expected.

What i do.

I export one product just change in Excel full description column and import same file.

We are on 3.8 and I exported, changed and imported it says the update was successful, but the old content is still there. I use to be able to update the content with no problem.