Unknown devices on my wifi ? Can't get it off

So i wanted to update my wifi password so i log intl my wifi setting and i seen there was alot of devices on my Wi-Fi I’m looking at them I noticed there were three of them that said unknown device. So i make a new password and save it my phone even logs out . i log in and there’s the tv wired( normal) … one unknown devices hooked up to my wifi and my phone
I try to Google all the info i could and there nothing i can find on what it is. I ended up blocking it manually from internet also notice that it was runing applications in my router setting . some china website pic the show

If there are unknown devices on your network it’s most likely a waste of time to block them because someone may have your WiFi password. There is no reliable way to block these devices.

You should reset your WiFi password to a secure password, then update the WiFi for all your devices.

I did reset the password as soon as I logged in for the first time it was ready running i don’t understand how ?

Interesting.

Perhaps these devices are your router or modem, or both?