After updating the theme, we’re sometimes unable to scroll down on the pages. This issue also occurs when editing pages with Elementor. I’ve disable plugins besides the required plugins but the issue still happens. I’ve tried using the Twenty themes and the issue went away.
Please deactivate all the 3rd party plugins and activate only theme-required plugins on the site and then check the issue. I am sure your issue will be solved. Then Activate the 3rd party plugins one by one and check which plugin is creating the issue for you.
Otherwise, if the issue still exists then keep the 3rd party plugins deactivated and share the wp logins details so i will check and give you a possible solution.