Hi,
PS: I also updated to WP 5.6
I’ve checked your site’s page source and an overlay issue.
<div id="swipebox-overlay" style="width: 1918px; height: 1764px;">
This exact issue is occurring on your site:
https://wordpress.org/support/topic/wordpress-5-6-issue/
That said, can you try disabling all plugins except GP Premium and check if it still occurs?
Perhaps you have Responsive Lightbox & Gallery or any other plugin that uses swipebox jquery library which causes this issue.
Let us know.