[2022] AC valhalla, too slow start then online service error

I bought the game on epic games.
So, I tried to run the game. It started as it should be, but after the "read it before play" screen, my game is slows down brutally. Half a hour when it finally loads the press a key button screen, and then another 15 min waiting. Then the game says: online service error
maybe Error code 0x7000015f.
I tried literally everything what I found on the internet but nothing seems to work. Not even a little.
Is my pc not stong enough (BTW theoretically the game should go without problem on my PC) or there's something with the epic games? For example I use different emails on Epic and Uplay. Could it be the problem?

My pc:
Win 10
Processor: Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz (8 CPUs), ~4.0GHz
Memory: 24576MB RAM
Available OS Memory: 24464MB RAM
DirectX Version: DirectX 12
NVIDIA GeForce GTX 1060 6GB