There was an unexpected disconnection from the server

Hello! From July 22 to July 23, I lost access to the game. When I enter my password and press Enter, it says "There was an unexpected disconnection from the server."
I tried to contact my provider, they asked me to trace back to the server. I traced to the address 109.95.212.141 (Moscow gateway). The ISP advised me to check with you to see if the ISP or any range of IP addresses was banned.
I'm sure I'm entering my username and password correctly.
And my Internet allows me to log in to the site. I can't exactly get into the game.
Just in case, the name of my provider is Beeline.
I also tried to enter the game by distributing the Internet with my phone (as a modem). It lets me select a character, but then takes me back to the login and password entry menu. And I can’t get into this gateway anymore. I chose other gateways (Frankfurt, Milan) and at first they also let me in to the characters, but then they threw me out and won’t let me in anymore.
I wrote to the provider again, and we tried to ping this Moscow gateway. The provider said that the signal comes from both their equipment and my home Internet.
I was strongly advised to contact the technical department of the game.
I do not use antivirus, firewall or Windows firewall. My ports are open - that's what the provider said.
Could you help me please. I've been playing PoE for a very long time. This is my life. And today there is a new league.
What should I do?

UPD:
I noticed another feature:
I could use gateways that I hadn't used before, like America, Washington. And they let me into the game if I quickly selected a character.
I tried different options several times, and the gateways that I used stopped letting me in.
And if I'm already in the game, it doesn't kick me out.
Maybe this will help somehow

UPD (2)
My provider says that the ping and route to the gateway (109.95.212.141 Moscow) are stable and since the connection is broken at the moment of authorization, it means that the gateway is blocking. They advise me to contact you so that you can see what is happening at the moment of connection.
Something else about the "gray" IP... They said that you should understand what this is about.
Please answer me?
Did I even give the provider that address?

UPD (3):
The provider gave me a static IP in the hope of improving the situation.
The situation has improved.
Now it can access the Moscow gateway. True, not the first time. The error is repeated several times, but another attempt is successful

Faced the same problem! Thanks to your post, I contacted the Beeline provider and changed the address to a static one. The problem is gone!