UTM 9 Slow Performance

Running my UTM 9 (latest soft release) under Virtualbox 4.18, I found it to be slower than my ASG 8.305 which also runs as a virtual machine on the exact same host machine. I restored the backup from the 8.305 system to the new system. Both virtual machines use the same number of processors (1), same amount of ram (2 GB), same network adapter types, and share the same physical hardware. In addition, I set the MAC address of the UTM 9 public interface to match the MAC address of the ASG 8.305 public interface. And, I can confirm that I pull the same DHCP address from my ISP. My site-to-site VPN connections re-establish themselves upon bootup on either system without the need to reconfigure my dynamic dns.

When the ASG 8.305 is running, my coworker and I get good performance from the web. When the UTM 9 is running, performance is degraded with long delays. I do not run the systems simultaneously as there would be conflicts with IP addresses. A wireshark trace shows many out-of-sequence packets when UTM 9 is running. My ISP does not currently offer IPv6 in my area, but I did set up a tunnel with Hurricane Electric on both systems.

Is anyone else seeing a slowdown in performance? If not, does anyone have any ideas why I would be seeing a lot of out-of-sequence packets? At the moment, I have shut down the UTM 9 and reverted to the ASG 8.305 and all is well but I would like to start taking advantage of the new capabilities incorporated in UTM 9.

Thanks,
Bob