Why can't I login to Outlook, Live.com, Microsoft, and Xbox on THREE?

[Veench]

I've recently switched ISPs. I was with Sky, and switched to THREE Home Broadband, which uses the 5G router. Ever since switching a week ago I've been unable to login to anything relating to Microsoft, including all the places listed in the title.

Outlook constantly gives me the "too many requests" error message when trying to login to my email, and when trying to sign into my Xbox account (either on the PC or through the Xbox itself) I get the error code 0x8007003B followed by "Something went wrong". I just can't login at all.  I also receive a message stating "Please retry with a different device, use a VPN, or other authentication method to sign in".

After reading for some solutions online, I found one that worked and that was to disable IPv6, although I don't know why this works.  Then again, it only works for a short while, and then I start receiving the error messages again and can't login.

I've spoken to Microsoft support, and they said that it's not an issue from their end and they recommend contacting THREE support to verify their IPv6 setup and request assistance with any potential routing or tunneling issues that may be preventing login.

I'm able to login to all these sites absolutely fine when using my mobile data which is not with THREE, but whenever I try to access these sites or apps on my THREE home broadband, I'm unable to.

[Veench]

I've tried getting in touch with Three's support via their live chat, but was receiving copy/paste type of responses that weren't relevant to my issue at all.  I was being asked if my sim card was placed properly in the router, whether the router was plugged in, etc etc (which if that was the case, I'd have not been online able to speak to them in the first place).

I'd love to find some way of getting in contact with Three to speak to somebody who knows what they're doing but I'm not sure how I can go about this.  Microsoft contacted me and told me to speak to Three about their IPv6 setup, but unless I were to speak to somebody who knows about this stuff, I worry that they wouldn't understand a word I'm saying.

[PeteG]

Hello there. 

I haven't come across an issue that affects all Microsoft services and nothing else before, but I have seen similar issues in the past where some services aren't working as expected. Some users on the Community have talked about turning IPV6 off, and often have had success accessing the services that were impacted. 

Pete.