Elementor + W3C Validator: “Attribute alt not allowed on element div at this point” for all photo gallery items [closed]

I am trying to validate my Elementor-built website using W3C Validator (https://validator.w3.org/nu) but when it comes for a page containing a photo gallery (Elementor Gallery Pro widget), I get the error:

Error: Attribute alt not allowed on element div at this point.

Obviously, Elementor applies the alt attribute to the div containing the image rather than the image itself, so this error is produced.

Any ideas how to fix it?

Thanks in advance!