Unable to install plugins

Hi Ben!

Thank you very much for your answer.

You just get the link here: Help! My Local site cannot establish a connection to WordPress.org

I have also tried to turn off protection (Kaspersky Internet Security).
Then, Defender, which has been switched off, will pop up and will block, but I reject it so it should.

I have it with my PC, as with my car. I’m totally lost when I open the engine or when others speak technical details about gearbox or the like.
Going into Powershell is the only solution I can see immediately.

How do I fix commands in CMD.exe, I do not know anything about.
I do not even know what CMD.exe is or where I find it.

To switch networks.
I have now tried that and -
It works! Hooray! Hooray!

As an emergency, I have mobile broadband.
I have tried this now, and so does Local by Flywheel seem perfect?

I’d rather use my normal broadband as it runs fast, but it’s obviously the fault here, so much thanks for the help.
Hope you might be able to help?

My router is: TP-Link Archer C2600.