Nem Wallet can't connect to any node

Hello,
I’m new to NEM, and it’s my first time using and setting up the wallet.
I currently have the problem that the wallet will not connect to any node. I’ve tried them all.

This is a problem with my internet connection, because I tried to install the mobile version on my android phone, connecting with WIfi, and got the same result.
I disabled all firewalls and restarted the router, it didn’t help.
I don’t have any problems with my connection outside of this.

Any ideas? I don’t know how to proceed from there.
Thanks

Maybe your internet provider is blocking ports: 7789 or 7778 ?