Resized images aren't changing

I recently installed this plugin to resize all of the images on a website, most of the images were around 1000×1000 and I reduced them to 375×375.

However after selecting the images I wanted to resize and then started the process none of the images were updated. All files were processed and I received the success image, however I cannot see any changes to any media files. There is also no reflection of any change to the FTP either.

Thanks,

Hayden

https://www.ads-software.com/plugins/imsanity/