Not sure if anyone else is experiencing this, but for a page, we've got a single repeating image field. When we click to add another image and get the upload image popup, we're having a problem with the search field if we go to the media library tab. The search field shows behind images listed, towards the bottom of the popup – see attachment.
Since it's hidden by images, we can input a value and search.
Problem remains even if we disable other plugin. All plugins and WP are up-to-date.