Widget text disappears after editing with PHPAdmin

I am cloning a website to several new sites with ManageWP. The cloning is working fine, but I need to change the contents of a bunch of text widgets for each new site. When I edit the content of the text widgets with PHPAdmin directly in the wp-options table, even if I just save it without making any changes, the text widget disappears from the sidebar. It looks like the contents is actually removed from the option_value field.

Is there any way to prevent it disappearing?