Yeah, I've seen this captcha loop issue happening more frequently lately! This usually means Facebook's security system flagged something unusual about your login - could be IP changes, device switching, or login patterns.
Here's what helps: clear your browser cache and cookies completely, then try logging in from your most familiar device/IP. If using VPN or proxy, turn it off temporarily. Go to Settings → "Security and Login" → check for any unrecognized sessions and remove them.
If the loop continues, wait 2-4 hours before trying again - sometimes Facebook's security system just needs time to reset. Try accessing from the official Facebook app instead of browser.
I've seen most cases resolve within 24 hours when you stop attempting logins and use familiar devices.
Are you accessing from a new location or device, and have you been switching between multiple accounts recently?