Minecraft offline even though i have internet connection?

I recently got a new PC and connected it with a Wi-Fi amplifier via Lan. Just somehow, the Wi-Fi amplifier now only makes weak Wi-Fi and Lan no longer. I already reset it, but it didn't work.

So I temporarily used the USB tethering method (share Wi-Fi from my cell phone to a PC) and it worked quite well, but then Minecraft always said "play offline" and the skins could not be loaded.

So I tried logging out and logging back in, but when I logged out I couldn't log in anymore, it just says "Sorry! Make sure you're online and try again". But actually I'm online, otherwise I can access everything that the Internet needs.

Can someone help me there?

If it helps, I have a Coredy E300 Wi-Fi amplifier

The amplifier is probably defective. And at MC try to close the game and restart the leek.

Please do not pay attention to the answer I accidentally wrote it

I've tried VictorMCGamer to restart the launcher often enough, also to turn off the firewall that publicly allows javaw.exe in the firewall…

And I know that the amplifier doesn't do anything right. We have the same one again in the house and it doesn't do anything anymore. But I did that with the USB tethering method with my cell phone on the PC and it now has Internet, I come into the browser and so in. Then why not in Minecraft

Then try to reinstall mc

Thanks already solved it so I didn't restart the router then I had internet again and everything worked