Strange grey color on gradient showing on mobile browser

Site URL: https://puma-orb-9lss.squarespace.com/projects

There is a strange grey color showing on my portfolio page gradient on mobile browser but not on computer browser. 

See images below for reference. 

Any knowledge on what might be causing the problem would be greatly appreciated!

Have you completed the site yet?

I see some small problems on your site.

1. URLs

I see some pages have url.

https://puma-orb-9lss.squarespace.com/about-1

https://puma-orb-9lss.squarespace.com/new-page-1

..

You can edit Page Settings > Change in URL Slug box

2. Some pages have long content on mobile, you can consider adding a back to top button

3. About page on tablet a bit narrow.