This check normally works without any problems. The bot/human verification is handled by Cloudflare, so it’s possible that a security app, browser plugin, or firewall setting may be blocking it.
You might also try temporarily disabling any “safe browsing” or similar protection in your browser, as this can sometimes interfere with the process.
As an alternative, you could try registering from a different device, such as your phone. Once registered, you can sign in from any device.