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.

[Nameless]

Band N78 is responsible for 5G speeds - Without it you will be limited to 4G speeds only

If you can access your router's setting directly, you should have an option to either change the bands directly and, if that is not available, an option to switch between 4G and 5G networks with Three's 5G network being the NR5G-NSA type due to also needing a 4G band to work

I have added the website you have used to my long list of websites to check and, if you have any more websites that usually have errors, please mention them here as some websites seem to be more error prone than others and for different users

Thank you for performing your tests

[MEid]

another thing to test is the Screwfix iOS app, it will never load with the three broadband but will load Ok with my usual mobile data. This is not fixed with only using band B1

[Nameless]

By any chance are you using the APN 3internet for your Three broadband? Sometimes that would cause issues for myself so I switched to using three.co.uk instead and it helped with some random errors however, all Three APNs do currently suffer from the PR_END_OF_FILE_ERROR issue

Additionally, is your phone using 4G or 5G? It may potentially be linked to that

Unfortunately I would need to update my phone to use that app and I can not do that at this time

[JonathanB]

Hi everyone,

Just to confirm, we're still looking into these issues, I'm awaiting some feedback on some internal testing following the info we gathered a couple of weeks back.

@andym00 and @Nameless thanks for the info about manual band selection, I've passed this on to my colleagues who are investigating, hopefully this helps the investigation.

It sounds like this settings change has helped in these cases regardless, is anyone else able to share if this impacts the frequency of errors when only connecting via bands B1 + N78?

Thanks,
Jonathan

[Nameless]

Hello and thank you for your update

I continued to test Bands B1, B20 and B28 with Band N78 and the PR_END_OF_FILE_ERROR issue is still there however they are far less frequent (Effectively rare in my case) compared to using Band B3 with no single website being a common breaking point...

I then started to test without Band N78 for a limited time however that would severely limit broadband speeds to the 4G limits and that is not really an option when paying for a 5G service... Needless to say, I did not encounter the issue in that limited test however it was not as intensive compared to my usual tests

My guess would be that there is some handover issue between Band N78 and the 4G bands which is magnified most with Band B3 compared to the others

At some point I used to be connected to Bands B1, B3 and N78 twice according to the router (An NR5103EV2) although lately it has been Bands B1 and N78 twice instead - I am not sure why

(For completeness, Cloudflare's WARP is only affected by changes to the overall broadband speed such as disabling Band N78)

I will continue with Band B3 disabled for now and will continue testing

[torz77]

I'm happy to test this, but digging around in my Huawei H122-373, I can see no location that the band selection can be altered. Am I missing something, or is this locked out on my router?

Edit: Scratch this. I've found a way to test this by hacking around in javascript. Will do a bit of testing when I get a bit more free time

[Nameless]

From my recent testing experience, it seems that Band B3 causes the PR_END_OF_FILE_ERROR to become far more frequent compared to Band B1 however it is still present on both bands but much rarer to encounter

If you are able to, try testing your connection with Band B3 disabled

[MEid]

Still having this issue, unable to use my work laptop unless I switch to my phone's hotspot so not sure if this is worth it anymore.

[Nameless]

To inform you all because it is nested, there has been an update
(You can put those pitchforks down for now but you may wish to use them for decorations tomorrow 👻 )

[JonathanB]

Thanks for linking this @Nameless. Okay I'll relent on this point. I don't personally like "no news" updates, but this issue has continued for an unprecedented time, so I'll commit to more regular posts on the thread until this is solved.

Whether there's news or not, I'll let you all know on Monday either way, and continue to update at least once a week.