This looping captcha issue with Cloudflare on Firefox for Linux is pretty common — it’s usually not Firefox itself but how Cloudflare’s bot checks react to Linux setups. A few things can help: try running Firefox in Troubleshoot Mode to rule out extensions, since blockers like uBlock or strict tracking settings often cause the loop; make sure “Resist Fingerprinting” is off in about:config, since Cloudflare flags it; update your system’s CA certificates so TLS checks don’t fail; and if needed, spoof your user agent to a Windows/Android Firefox, since Linux agents sometimes look unusual to Cloudflare. Also check your DNS settings (disable DNS-over-HTTPS or switch resolvers) and be aware that sometimes it’s just your IP reputation, so a different network or VPN can bypass it. In short, Firefox works fine, but Cloudflare is stricter with Linux, so a few tweaks in settings or environment usually smooth it out.