Null process and missing media images

I have tried to do a bulk process & single optimization but it would never start the process just a delay after which i would have to close down the window. On attempting to log back into wp I would have to wait a few min before being presented with log in page. On returning to media library my image/s that was to be optimized goes missing completely but the data still there.

Must add I have had the “all clear” to use the plug in and my images are mixture of sliders/page images

Thanks

https://ww.wp.xz.cn/plugins/ewww-image-optimizer/