One of my home IP addresses can't access sites hosted in Azure

Hi,

I have a slightly odd issue - traffic coming from my default home IP address (82.68.8.222) seems to be being dropped by some websites hosted on Azure (Microsoft learn, Nationwide Building Society). If I masquerade my laptops as coming from a diffierent IP address within my /28, it works fine. I get the following errors:

https://answers.microsoft.com

 The request is blocked.

20250402T135552Z-18568544f9chlv2whC1LONk4ms0000000fk0000000006u49

Nationwide Building Society:

Nationwide Building Society Sorry, our link hasn’t worked To try again, please refresh this page. To go directly to our website homepage, click www.nationwide.co.uk, or type into your search bar. 20250402T135626Z-18568544f9c6hrtnhC1LON9us40000000f6g00000000385w

I can access the usual Azure admin stuff without a problem, it's just sites hosted in Azure that seem to block me.

Any ideas? Can I check if that IP address is on a blocklist of some sort and, if so, how do I remove it? I've had that netblock for a long time and, as far as I know, it's not been used for any malicious purposes!

And, given that it affects more than one website, I doubt whether it's a site-specific setting.

Cheers,

Phil