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.

[BrummyGit]

With the help of a user on another forum, I have worked out that my consistent inability to reach certain websites is due to the Adult Content filter (even though they aren't adult sites). Turning it off has resolved that issue.

I have a slim hope that it also solves the intermittent secure sites problem, but I honestly doubt that. Time will tell

[robjames_1]

That website seemed to work just now for me but have been having similar issues for a couple of months. 
Notably online payments and online banking apps are hit or miss. Disney plus, and my5 don’t work but strangely Netflix and prime do. 

[EDIflyer]

Yep I find online payments particularly buggy - just at the time you don't want a transaction to fail!

[JonathanB]

Thanks @BrummyGit, I'm sorry I didn't get a chance to reply but we passed this example over last Friday too.

[AlSeek]

I had switched to using a 4G connection the last 3 weeks after it was mentioned by @Tatablack this does not exhibit the connection issues (although I wouldn't consider it a solution as the speeds are slower) and my experience is that the issue doesn't occur on 4G EXCEPT the last week I have repeatedly experienced the issue when navigating to Wikipedia only. Nothing else just Wikipedia. So the hypothesis that it is only 5G affected doesn't seem wholly true, although on 5G it is many many websites affected whereas 4G I've only experienced this one website affected. I hope it doesn't get any worse on 4G.

[Tatablack]

I can confirm. I switched to 4G tonight because I needed my GitHub connections to be reliable (now they are), but indeed I still have problems with Wikipedia or malkoffdevices.com. Puzzling.

[JonathanB]

Hi @Tatablack,

Thanks for confirming this. It seems like the issue must be a complex one but hopefully this will help the team unravel it.

Thanks,
Jonathan

[BrummyGit]

I think it's my fault that the issues around some sites such as malkoffdevices.com are being discussed. I was helped by a user on another forum and turning off the Adult Content Filter resolved all of my permanent connection issues (but not the intermittent ones that are the main subject of this thread), so sorry I think this was a red herring.

[kris]

Same thing.

Error code: PR_END_OF_FILE_ERROR all the time!

I had ZYXEL NR5103E and switched recently to HUAWEI H112-370 (5G CPE PRO) - no change at all, exactly same behaviour, so 100% it's THREE fault. I'm in full 5G signal.

God it's so annoying when it drops the first connection on the browsers. It also does it to my TV EPG so sometimes I have to refresh it few times to get programme list!

[JonathanB]

Hey @kris,

Thanks for confirming that this is an issue with the Huawei device too. It seems like it's mainly a 5G issue, some users have found 4G is connecting without this error, with a couple of exceptions, but it seems to vary between different sites. We've gathered some example account details, and I'm passing on any community feedback to help with the investigation though, so hopefully this shouldn't take too much longer to resolve.

Thanks,
Jonathan