Hey, I'm glad you liked it, yeah that's normal, you can't kill but you can be killed because your character is actually standing still until you resume the internet connection. Nonetheless I tried to see if I could keep the incoming data, so you could see what's happening in real time while you're lagging, but it wasn't successful for CrossFire. If you'd like, click at the Donate button to know more contact info, so we can try doing that for Fortnite and see if it works.
For Windows 10 follow Start>>Settings>>Network & Internet>>Windows Firewall, there you can check whether it's enabled or not.
P.S.: There's a newer, better version of this program, you can download it here: https://www.mpgh.net/forum/showthread.php?t=1562209