WebP Images – Converting Image staying on 201

I’m currently trying to convert existing images of my site to WebP format but every time I click the toggle to take this action the process sits on “Converting Image 201 of 1040…” and doesn’t progress up.

I’ve cancelled this action a couple of times throughout the day and started again with the same result. Previously I had an issue with the Image Compression toggle with the Rest API but have resolved this by putting my Wordfence plugin on ‘Learning Mode’. This new issue is with the WebP Images only and no Error messages come up to let me know what’s wrong.

The page I need help with: [log in to see the link]