For the most part, we see this when there is conflicting software that restricts the needed connection to the Launcher / Game Client.
You might need to temporarily remove some Security Software you have installed on the PC, or perhaps lower some Security Settings on Windows Firewall / Windows Defender, then restart the computer and check to see if the Launcher functions as intended.

If still no luck, please feel free to submit a Support Ticket and our Agents will be happy to assist. :)