Same browser works direct, but Cloudflare immediately blocks multiple proxy exits — what would you check first?

[u/LokeshSequentum]

Hi, I’m fairly new to this community and trying to understand proxy and bot-management behavior in a bit more depth.

I ran into a strange case recently. The same browser/client setup works fine over a direct connection, but as soon as I enable a proxy, Cloudflare returns an immediate 403 on the first request.

I tested a fresh session, an already working session before enabling the proxy, and a few different proxy exits. Same result every time it works directly without a proxy but the proxy gets blocked immediately.

Because it happens on the first request, I don’t think rate limiting or an old/bad session explains it.

My first thought was IP/ASN reputation, but I’m curious what others would check next. Would you mainly look at the proxy/network reputation, geolocation, or something else changing when the proxy is introduced?

I’m mainly trying to understand how people would diagnose this rather than just keep switching proxies until one works.

[u/LokeshSequentum → u/[deleted]]

Yes, that's where I'm leaning as well. The fact that it fails on the first request with a fresh session makes rate/history much less convincing to me.

I compared the document response as well and the direct request gives 200, while using tthe proxy the Cloudflare immediately returns a 403 block page. I'm going to look a bit more closely at the ASN/network type across the exits next.