Hi!
Do you mean you can’t connect to https sites or that after successfully visiting a https site the internet goes down? Which https sites are you using for testing?
Try flushing the ipatables before running the attack:

iptables –flush
iptables –table nat –flush
iptables –delete-chain
iptables –table nat –delete-chain
iptables -P FORWARD ACCEPT

Enable port forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward

Then it might should work fine.

Greetings!
Diego