I'm seeing a strange issue where some of our image styles seem to be broken while others work fine. The broken ones are showing the typical signs of the source image existing while the image style url used on the page is broken. I can't seem to find any consistencies -- similar effects are used on working and broken styles, and some broken ones are defaults (thumbnail) while others are customized. Quite odd.
Any ideas what might cause this? Site is running D9. I'm hesitant to purge the image styles in case it doesn't work and we end up with even more broken images.