I can add Palemoon x64 & Edge to the list of working browsers.

iPhone 5s Safari and BT Broadband ... works for me

Using IE11 on Windows 10, after entering my phone number and clicking OK I got a small whirling gadget for a few seconds, then it stopped.

I was about to agree with you, but then scrolled down, where the result is there but effectively "hidden" in the blue background. The screen as a whole did not refresh in the way I expected, and you may have expected the same. The results appeared below the visible part of the page.

In reply to a post by RobertoS:

Using IE11 on Windows 10, after entering my phone number and clicking OK I got a small whirling gadget for a few seconds, then it stopped.

I was about to agree with you, but then scrolled down, where the result is there but effectively "hidden" in the blue background. The screen as a whole did not refresh in the way I expected, and you may have expected the same. The results appeared below the visible part of the page.

No whirling thing - just a big empty space no matter what I put in...

FF - 53.0 x64
IE - 11.0.41 x64

IE doesn't even give me the box to enter a number/postcode, FF at least will.

Screen shots on picpaste

IE Fail
FF Gives me the box
FF After entering a postcode/number

Do you have any ad blockers installed? Wondering if the ad blocker is for some reason blocking some of the page components.

Not as such but there is aggressive network level blocking going on. I've checked the logs & nothing is being blocked or denied.

Just tested with TOR - Same blank page section. (So that rules out any network level blocking etc)

Had a quick check in the console as well - the only thing I see is a POST request to https://api.superfastmaps.co.uk/openreach/1.2/ then nothing gets returned.

I'll have to have a try on a couple of other networks / machines and see if I can reproduce it elsewhere.

Are you still with Zen, as per your forum profile?

Yes

That figures. I have the impression over a year or so that not everything there is perfect over things like this. Nothing major that can really be tied down, just several small things like this.

In reply to a post by RobertoS:

That figures. I have the impression over a year or so that not everything there is perfect over things like this. Nothing major that can really be tied down, just several small things like this.

In what respect? I've actually had very little trouble with Zen TBH but things have in general gone down hill from the customer side of things - there not like they used to be...

Are you hinting that this issue with page displays may be network related to Zen?