page jumps on when submit form

Hello,
I have a form at the bottom of the page.
when I try to submit the form using google chrome in mobile devices only the page jumps up.
my wordpress and all plugins are up to date.
I am using my onw custom theme.
I disabled all plugins and switched to twenty twenty theme and this issue still happeining.
How can I fix it?

The page I need help with: [log in to see the link]