Certain XLSB files are failing on upload

Hi,

What could be the reason why certain xlsb files, I am getting this error - however it does not make any sense.

Note: I can;t share the actual file since it contains sensitive information.

"Sorry, your files couldn't be uploaded. The upload might be too large or the server might be experiencing high network traffic."

- File is only 2MB
- other xlsb files can be uploaded together with any other file types

- I don't think the file is corrupted as I can open it normally.

What should I look into?