My Xiaomi Redmi Note 8 Pro tethers with the router, but has problems accessing the internet. I have checked other devices for this problem. All xiaomi smartphones tested had the same problem. But other devices had access to the internet. 

Here is a list of smartphones that have problems accessing the Internet: Xiaomi Redmi Note 8 Pro, Xiaomi Redmi Note 10S, Xiaomi Redmi 8A, Xiami Redmi A1. And here is the list of smartphones and tablet that have no problems: Fly IQ456, Huawei Y5 2018, Flylife Connect 10.1 3G 2.

Internet is not completely unavailable on xiaomi smartphones. If you go to Telegram and wait about half a minute, then Telegram is completely loaded. It is absolutely the same on every xiaomi. Earlier, the YouTube main page was loading. Now it won't load. Other applications do not have access to the Internet.

I have already reset the router to factory settings a dozen times. Nothing was changing. No xiaomi has a working internet connection.

Help me please. I have no idea how to solve such a strange problem.