If you're using a proxy, then 99% of the time the problem comes from the proxy itself. It could be the type of proxy, like datacenter or IPv6, or the IP you're using is already blacklisted by the platform. This might happen due to spam or some previous abuse linked to that IP.
The remaining 1% might come from your browser's fingerprint not matching properly. That includes things like timezone, WebRTC, or other details that don't align with a real user's setup.
So if you're using a proxy, try switching to a different one or test another provider. If changing proxies doesn't fix the issue, consider using an antidetect browser like GoLogin, Hidemyacc, or Multilogin.
If you're not using a proxy and just relying on regular Wi-Fi or mobile data, it's possible that you're getting flagged because of too many actions in a short time. The platform might think you're a bot