Intermittent connection issues loading/changing site- secure connection failed/site can't be reached

[EDIflyer]

Is anyone else occasionally getting a 'connection down' error from Chrome (or 'Secure Connection Failed' from Firefox) when changing page - if I hit refresh it works fine. At first I wondered if it was the site I was using but have noticed it on multiple different major websites over the past couple of months and not noticed it from other locations where I don't use Three Broadband so does seem to be related to the router/connection (this is via wired Ethernet too, so not a WiFi problem).  I've tried changing DNS server in case that helps but no difference.

It mainly seems to happen when trying to first load a site or (annoyingly) at checkout when a different site is being loaded as part of the checkout process.  It certainly doesn't happen everytime but does happen with reasonable frequency.  I've also noticed I often get it when trying to pull/push from/to Github too and have to do so a number of times for it to work (browsing the Github website works fine).

I'm using a NR5103E with Firmware Version V1.00(ACBJ.0)b14 - I tried rebooting it but to no effect.

[torz77]

Just checking in to say, no change here. Issue still persists.

Lets hope 2025 can be the year that Three finally solve the issue.

[AlSeek]

A question for those who have a Three SIM and also are using a mobile virtual network operator (MVNO) on Three's network...
Any MVNOs on Three's network not experiencing this issue?

[Nameless]

As far as I have tested, all Three MVNOs have this issue - You can test each one by changing the APN details and that is what I do when I test things

[Nameless]

Just a quick check-in

I moved the router and tested both Wi-Fi and Ethernet and the problem is still there although it took longer to see it as I have been connected to Band B1 lately despite all bands being enabled

Usually, if I am connected to Band B3, I encounter the PR_END_OF_FILE_ERROR at some point whilst going through the list of problematic sites once. Today I went through the list twice in immediate succession then started a round of speed tests for ~15 minutes due to the router's new position being closer to the nearest mast by ~3m-5m. After that, I encountered the problem when going through the list for a third time

The router's last uptime was ~51 days if I read it correctly before turning it off

How are things for all of you?

[AlSeek]

More or less the same as usual for me. As mentioned long ago in this thread, I am running my router as 4G only and get the connection issue infrequently. In 5G mode I get the error frequently. So that may be band related or maybe not, I don't know.
I have tried going on 5G and disabling band B3 which made no difference to me since I still got the error quickly.
Indeed connected by 4G right now I'm apparently on bands B3,B32,B1 and the issue is currently infrequent.

[Nameless]

The error is definitely somewhere in Three's infrastructure although I have not tested any of the 4G bands alone as extensively as I have tested them in combination with the N78 5G band

Have you tried the 4G bands individually? It would probably have the biggest impact on your speeds compared to using a VPN or Cloudflare's WARP although these are currently the only known methods of avoiding the highly variable PR_END_OF_FILE_ERROR completely

I will try testing the 4G bands individually when I get time

[EDIflyer]

Did anyone else have major issues last night? I found from about midnight until 9am my internet was completely down unless I used a VPN.  Phone showing an exclamation mark over wifi and 'offline' in Chrome, PC wouldn't connect to any site. However once VPN activated then all working OK - it was like a more extreme version of this issue!

[Nameless]

Thank you for mentioning this

My internet has become somewhat more unstable in the last few days however, apart from when I have been doing tests, my main indicator is that the Amazon Fire TV has been stuttering a lot over the last few days but this has been far more noticeable on higher resolution streams (FHD+) and for content that uses a high frame rate

[JonathanB]

Hi @EDIflyer,

I've had a check and we don't have any major widespread incidents reported, so it might have been more local of an issue. Glad to hear it was relatively short term and seems to have been fixed this morning.

Were the browser errors matching the usual "end of file" or "connection closed"?

Thanks,
Jonathan