I as well have been suffering from the same issue.
For a few weeks now, I have started to really notice, that any website using Cloudflare’s Turnstile, will absolutely not let me through.
I click box, it spins & tries, it silently fails and restarts the widget, I click box, spin&try, restart, click, spin, restart, , , (∞etc∞)…
I tried everything and them some… Then spent several hours in DevTools trying to figure out what was wrong…
Today I finally found the answer in the sources in some HTML hiding in the back end, that told me my browser is out of date . I’m not sure why it doesn’t display it for the user to see. It would’ve been nice if it would have and told me days ago what the problem was.
My Macbook is little a bit older than yours must be, and is “up to date” with MacOS 11.7.10. I assume that all Macs over a certain age using Firefox will encounter the same rejection.
My Macbook Pro was made in 2015, and I still prefer it to their latest models for several reasons. However I’m unhappy it is having compatibility issues and cannot be updated to the latest versions.
Lately more and more things I use no longer support my machine. I have everything up to date, to the latest compatible versions (MacOS11.7.10|Firefox134.0), yet I’m rejected and classified as outdated.
All started a few months ago when I finally gave in and updated to Big Sur. I lost a couple pieces of software I use. The installed version became outdated for my OS, and then when I tried to update, my new OS is too outdated for their updated software.
I feel like my OS is really the only thing that makes me incompatible. My hardware was top-of-the-line in its day and is more powerful that many new machines that are compatible with newer versions of software that deem me incompatible.