Error 403 on Google Adwords for a certain IP, Google says that the problem is with the provider / hosting. How can this be?

Question

Google

All my life I thought that the 403 error is an access error that the server gives (on which the service is raised).
As for me, Google just banned our IP for the adwords service.
But Google Adwords support claims otherwise.
How can this be?
We have a server hosted in Moscow that runs our application using the Google Adwords API. It recently suddenly stopped working.
In curl, we see 403.
Especially in order to be able to show support images, they raised the proxy.
The symptoms are very simple when you try to request
https://adwords.google.com/
https://www.google.com/adwords/
A Google-style 403 page appears.
Another similar address opens without problems:
https://www.google.com/analytics/
Also everything is fine from other IPs.

The hosting provider assures that the problem is on the side of Google (and I myself think so).
Google support answers the following:

I contacted our moderators about your problem and we checked the availability of the site from our side. It turned out that the only possible reason for the inaccessibility of the site lies with your Internet provider. I recommend contacting him directly.

We asked again about the fact that the page is clearly given by the Google server, received the following answer:

Yes, this error is generated by Google, but it displays it for the reason that you are denied access to this page from your server. Google, in turn, maintains open access for its resources.

We clarified again that how can it be that via HTTPS , on the same domain, but with different paths, one page opened and the other did not, and it was a provider / hoster problem, we specified the IP, asked to re-check and received this answer:

I once again turned to our moderators. All our experts confirm that Google AdWords does not block access for this IP and for other Moscow IPs. When an error 403 is displayed, the system writes information that you do not have access to this page from this server. The same is written on the screenshots that you sent me. From our side, public access is open. The problem is clearly on the part of your server, browser, or operating system.

The hoster advised downloading the pages on the server via ssh with curl. But it's the same there. The same source code of the pages and the same text.
Where to dig? How can this be? Maybe I'm missing something and the problem is really on the side? Maybe something has changed lately? Maybe this is Roskomnadzor blocking on separate URLs in HTTPS?
Thank you.

Answer 1

dig into the tracerout , domains have different IP
how to determine the IP - the good guys from Microsoft made a list of possible reasons sent by your server

Answer 2

Thanks to all.
The hoster found out that the problem is in the whole subnet.
Google banned an entire subnet.
They will figure it out.