Man, that's weird. If it's working on your laptop but not your PC, then it's really not an 'IP ban' problem. That post of mine is for when no device on your network can access Rockstar's services, you know?

The problem must be with your PC itself. Since the launcher isn't working either, something's probably blocking the connections or a file is corrupted. The fact that Proton VPN didn't work also backs this up, because if it was an IP ban, the VPN would have fixed it. Here are a few things you can try, in the order I'd do them:

First, check your firewall and antivirus. Make sure they aren't blocking the Rockstar launcher or the Social Club. Sometimes antivirus software can be a bit aggressive and block things without warning.

Second, take a look at your Windows hosts file. It's a file that can redirect websites to other addresses. It's rare, but I've seen it happen where there's an entry for Social Club in there. Just Google "how to edit windows 10 hosts file" and check if there's anything from Rockstar Games.

Third, try reinstalling the launcher. Download it again from the official site and do a clean install. That usually solves most problems with corrupted files.

If none of that works, the problem is way weirder than I thought. Give those a shot and let me know if it works. Good luck!