Hello. I’ve just created an account to comment on this as I’ve been experiencing the same thing since early January 2020.
My setup consists of a Huawei E3372 USB dongle, acting as my gateway. The dongle is connected to a router which handles DHCP and a NAS which handles my internal DNS.
The problem:
I’ve been having problems navigating to web pages. It is very intermittent and only happens around 50% of the time. If a page is failing to load, I click refresh again, and it magically starts working, most of the time.
Using Wireshark, I’ve determined that this is an issue within Three’s intranet. More specifically: The TLS handshake/dance and its associated packets are either getting dropped or being routed incorrectly within Three’s intranet.
This appears to be a configuration problem that can only be solved by the ISP.
I’ve also observed that this only applies to their unlimited broadband packages. I have no problem with their capped 100GB line on my actual phone. This may be due to the fact that their unlimited packages implement CGNAT, and have no ‘public facing’ IP. That, however is just speculation.
The solution:
I have solved all of these issues by creating a VPN tunnel and forwarding all outbound traffic through that VPN.
The fact my ‘gateway to the Internet’ is extended to the VPN endpoint when using it (i.e. establishing a TCP connection to the VPN and putting all my traffic through it, thereby not traversing through ISPs intranet) kind of backs up my case that it is a configuration issue at the ISPs end.
i.e. TLS packets are routed through the established VPN TCP connection.
Three’s response:
I’ve contacted Three around ~6 different occasions since then. It appears that nobody seems to have a clue what the issue is, and the responses I’ve got are basic cookie-cutter advice at best.
Even their ‘technical team’ appear to have no real understanding of the issue, and will not raise an issue because ‘their testing’ has determined that there are no problems.
I’m very worried for the company, and it’s perceived mismanagement.
All of this is anecdotal, but I hope the VPN solution works for other folks who have stumbled across this article.