Issue with sharing a URl to Facebook and Threads.

When I use the debugger, I receive the error:

Provided og:image URL, https://images.weserv.nl/?url=openbenches.org/image/9b509b8e81f3f522f6ef3ce713854b9732b16fd3/&w=600&q=60&output=webp&il could not be processed as an image. It may be corrupted or may have an invalid format.

The image is a valid WebP. I've also tried it with a valid JPEG which also gave an error.

The URl is https://openbenches.org/bench/35156 and the HTML is:

<meta name="twitter:image" property="og:image" content="https://images.weserv.nl/?url=openbenches.org/image/9b509b8e81f3f522f6ef3ce713854b9732b16fd3/&amp;w=600&amp;q=60&amp;output=webp&amp;il">
<meta property="og:image:type" content="image/webp">
<meta property="og:image:width" content="600">

Every other OGP tool reports that the image is valid. For example https://www.opengraph.xyz/url/https%3A%2F%2Fopenbenches.org%2Fbench%2F35156

There are no blocks in the robots.txt, the image is being served correctly by CloudFlare, the image filesize and dimensions are within the allowable range, the URl is properly formed.

Please can you let me know what can be done to resolve this bug?