Upload by clicking the ‘Submit Assignment’. Be sure you are uploading the file that ends with .xlsx or .xls.
To check your upload, look at the submission information on the right side of your screen and 1) download a copy a copy of your project FROM Canvas to another folder on your computer. 2) Open this copy, be sure it’s the right project, etc. and then 3) close / save this copy. This is your back up copy and the creation and last modified dates will be retained as long as it is unopened.