Hello @wheezard ,
This may be a conflict with your theme or another plugin. Please try switching your theme to a default WordPress theme, such as Twenty Twenty-Five, or try disabling your other plugins one by one to check if the issue can be reproduced. If you have any plugins that modify the WordPress Media Library, I recommend starting with those.
Next, please edit one of your galleries, open your browser console (press F12 on your keyboard and go to the Console tab), and look for any error messages. Then repeat the steps that trigger the issue (add items to your gallery so that others are removed) and check again if any errors appear.
We currently do not have any other reports of this or similar issues, so it is very likely related to a plugin, theme, or custom code on your website.
If you are unable to identify the source of the conflict, please send us a screenshot of your active plugins and screenshots of any console errors at:
https://wp-modula.com/contact-us/
Have a great day!
