Pls check if you're using special characters in the data like comma.
If so it may consider it as delimiter.
And you can always check the preview to see how the column values are mapped
Apart from suggestion provided above, you can try the bulk update for 1 or 2 records to isolate the issue. Preview will also help.
Mostly should be data input present in the Excel sheet, Additionally please validate if you have any relevant cleanse transformations that tweak the data are defined for this BE/BEview.
Please check if there is any cleanse function trimming the data.
Also share screenshots and cmxserver logs for import process.