[Baertram]

Blackpad and rumple: You 2 seem to suffer from the same issue.
Maybe try to find out what your setup got common (e.g. are you using the same location and/or internet provider, or a fixed IP address, or the same antivirus/firewall tools, etc.).

I'm not having any issues with multiple captchas, never had. And a lot of other guild mates neither do, so it must be something (as cyxui already answered before) with your setup/country/ISP/IP address/VPN (you both don't use any)/proxy server?/cookies/...

Is it only the TTC website or do you experience the same at any other website (as the captcha service is a Google one's afai understood)?