Last week I had a run of (legacy) Cloudflare captchas on sites protected by CF to solve of "select all the boxes with motorcycles in", and despite doing it fastidiously and correctly (although I never know how to handle the boxes with like 3 pixels of object in but are otherwise clear), I had to do it like 5 times with different images, until suddenly it was happy.
Are you sure it's not fake? For example archive.is sometimes sends me orange-colored CAPTCHAs (with "select all the boxes" style) that are never accepted; but if one looks closer at them, it actually never says "cloudflare" on them anywhere, nor there is a logo (it does this because it has a long-standing feud with cloudflare re users' privacy).
I thought they had as well, which was why I was surprised to see them.
I can't remember the site I saw them on, so I don't know for certain, but the site was definitely protected by Cloudflare, and I'm not really sure what you mean by "fake" - they were definitely CAPTCHAs with image tiles, but I guess I don't know for certain they were coming from Cloudflare servers.
Archive.is made their own check page (probably based on HCaptcha), which uses same color scheme as cloudflare and same general design.. except if you look closely, you'll notice there is no word "cloudflare" anywhere on page, it's a homegrown solution: https://www.reddit.com/r/SaintMeghanMarkle/comments/18c3ea7/...
For some weird reason, people like to attribute every captcha to cloudflare, even if they no longer offer this service...
Last week I had a run of (legacy) Cloudflare captchas on sites protected by CF to solve of "select all the boxes with motorcycles in", and despite doing it fastidiously and correctly (although I never know how to handle the boxes with like 3 pixels of object in but are otherwise clear), I had to do it like 5 times with different images, until suddenly it was happy.