Image visibility problem after the latest update

Everything was working fine until the latest update ’ 2.5.0.beta3’
and then I discovered that many (but not all) of the images are no longer visible. When I post new images they work fine, but I can’t repost all the past images of the whole forum again of course.
I am using a self-hosted version along with CloudFlare as a CDN. I turned off the caching of my CDN provider but that didn’t help. So what to do please. Thanks for any help.

Can you share a link to a post that reproduces the problem?