Yes sir. there are two ways. either you can reset all images in our dashboard and refresh the page and all images will again appear. or if you dont want to reset images click on media list view and you can see all images regenerated by plugin.
If you reset if our dashboard you are not losing anything only the plugin erases data of already regenerated images so that you need not to regenerate same image again. its our data , our means plugin data about your images it regenerated thumbs so without any second thought click on RESET ALL IMAGES and refresh page. we start automatic regeneration only first time as people thinks that its paid plugin so its our way of saving no no its not paid. its free