Why do some providers block a domain that is not in the registry of banned sites?

Question

Amazon Web Services

Greetings.
In our country, after blocking Amazon IP addresses, users of our service began to complain en masse that they were not loading pictures from the amazon s3 storage. We started the traffic through a proxy - it worked, the complaints stopped, but this is an unreliable solution. Working with s3 directly is, of course, much better.
The problem concerns the eu-central-1 region. For example, let's take this standard URL for the s3 storage:
https://s3.eu-central-1.amazonaws.com/rkntest/img.jpg
On most providers, it loads normally, but, for example, it does not work on the mobile Internet of MTS and Megafon in Moscow region (and maybe not only). And judging by the number of complaints from users from many other providers, too.
The strangest thing is that if you nslookup this domain and check the IP addresses in Roskomnadzor, then they are not in the registry.
Can someone tell me how it turns out that the domain and its IP addresses seem to be absent in the registry, but at the same time s3 does not work on some providers? And how to convey this problem to Roskomnadzor?

Answer 1

In the first days of the Runet blockade, the Agora human rights organization received more than 120 appeals from the owners of websites and services affected by the actions of Roskomnadzor. The organization's lawyers recommend the following legal response algorithm:
The general legal response algorithm is as follows:
In early May, Agora plans to collect all the facts and file an appeal to the Prosecutor General's Office to verify compliance with the legality of Roskomnadzor's actions. Then a class action lawsuit to the European Court of Human Rights looks quite realistic, Agora believes.
Source.

Answer 2

On my usual providers - Avantel and Dom.Sru - the link is loaded normally. Picture with swans.
"The whole world knows about it" (C) Woe from the mind of the
RKN drives a cart, and addresses that have absolutely nothing to do with it fall under its friendly fire. It's like a terrorist trying to hide in the crowd, hoping that they won't open fire on the crowd.
IT does not exist in a vacuum. It exists in a state that has a policy, etc. Therefore, well, it is impossible to do with "pure IT".
The RKN, let's say, got into the same not very pleasant situation that Trump was in Syria - he puffed up a lot and in the end was simply obliged to attack it. And, of course, "I will win everyone." The same goes for the RKN - he also puffed up a lot, rushed to fulfill the court decision to block the cart with direct zeal, like a kick-ass - and now he simply has no way back.
If the RKN now hangs around, starts saying that it can’t cope with the blocking, etc., then it will become clear to everyone that these court decisions on blocking can be put in the middle, no keys can be given - they still won’t be able to do anything.
Therefore, the RKN will fight to the bitter end. And this, in my opinion, few of those gathered here understand. Just like Trump in Syria. Stopped Tramp by the OPCW? Yes, he put it on him with a parting. So it is here - the RKN will put on the ECHR, no matter what decision is made there, and Carthage will be destroyed . Telegram will be blocked in the Russian Federation, even if this will have to switch to white lists. There will not be enough technical tyama - they will attract administrative resources. How do you like, for example, the Criminal Code of the Russian Federation, Article 205.1 (complicity in terrorism)?
Here I already wrote in some comment above - if you think that everything is over with the missile attack in Syria - you are critically mistaken. Everything is just beginning . If we take the twentieth century, it is now approximately 1936, the beginning of the civil war in Spain. Further, the nuts will tighten more and more.