Bug: Default image size deleted

Hello! I found bug I would like to report.
If we have an image size registered by a theme or plugin at the same size with one defined in the Media page ( Thumbnail, Medium or Large ), when we press optimize, that image is deleted. And since the default sizes are not generated on the fly, we end up with missing images.
The only way to solve this issue is to force regenerate thumbnails but by doing so we end up with all the image sizes back on our server.

https://www.ads-software.com/plugins/optimize-images-resizing/