In order to troubleshoot this issue, please follow these steps:
Open your Network Ports
https://portforward.com/hell-let-loose/
DNS Flush
- Click “Start” and type the word “Command” in the Start search field
- Right-click the command prompt icon and select the option to “Run as Administrator”
- In the open prompt, type “ipconfig/flushdns” (without the quotes)
- Retest
Turn off IPV6
- In the Windows Control Panel, go to Network and Internet, press on Network and Sharing Centre.
- Press the Change Adapter Settings button, and RMB on the network you are currently using, this could be Ethernet or WiFi, and press Properties.
- In the following window, disable the IPV6 checkbox and press OK to save the changes, restart your PC
You may need to tick and untick this if the option is already off.
If this does not help, please try to reinstall the game and retest.