ERR_QUIC_PROTOCOL_ERROR and ERR_CONNECTION_RESET errors with Cloudflare Proxy

[mr.shavkat.kurbanbay]

What is the name of the domain?

neoinsurance.uz

What is the error number?

ERR_QUIC_PROTOCOL_ERROR and ERR_CONNECTION_RESET

What is the error message?

ERR_QUIC_PROTOCOL_ERROR and ERR_CONNECTION_RESET

What is the issue you’re encountering

Random ERR_QUIC_PROTOCOL_ERROR on some clients with Opera, Chrome browsers

What steps have you taken to resolve the issue?

Disabling HTTP/3 on Chrome and/or on Cloudflare proxy - changes error from ERR_QUIC_PROTOCOL_ERROR to ERR_CONNECTION_RESET, but website anyway not working
Seems like there is no problem on Firefox or other non-chromium browsers
Seems like in most cases all users who encounting this error is using same ISP Uztelecom, but because it’s most common ISP in our country there is no chances to change it or something else
Incognito and cache flushing, flushdns and other actions don’t give any results
Seems like VPN is fixing problem
Basically we need a solution to keep proxying in cloudflare, but with changing settings on Cloudflare side to make Chrome works same as Firefox or other non-chromium browsers, or detect which exact protocol or something is conflicting in scheme Chrome → ISP → Cloudflare, but keep work in non-chromium → ISP → Cloudflare scheme

What are the steps to reproduce the issue?

Open neoinsurance.uz website

[DarkDeviL]

@mr.shavkat.kurbanbay

ISP Uztelecom

Can you share the AS number?

The AS number can be found here:

• https://1.1.1.1/help
  → AS Number
• https://bgp.tools/
  → The AS number shown under “You are connecting from” like this: “Cloudflare, Inc. (AS13335)”
• https://bgp.he.net/
  → The AS number shown like this: “Your ISP is AS13335 (Cloudflare, Inc.)”

@mr.shavkat.kurbanbay

Seems like there is no problem on Firefox or other non-chromium browsers

Can you confirm that this is being tested on the exact same network(s), where the one actually works, but the other one doesn’t?

@mr.shavkat.kurbanbay

Seems like in most cases all users who encounting this error is using same ISP Uztelecom,

&&

@mr.shavkat.kurbanbay

Seems like VPN is fixing problem

Based on your explanations here, such as e.g. that it relates to one specific ISP, and that a VPN is fixing the issue, -

I would typically suspect the Internet censorships of Uzbekistan to be the culprit to the issue that you’re seeing.

Perhaps together with:

The unintended consequences of blocking IP addresses

@mr.shavkat.kurbanbay

Basically we need a solution to keep proxying in cloudflare

Have you tried pinging and running a traceroute to your domain, while it was set to Proxied (), and if so, - what was the output?