Sophos XG: Bad latency when QoS in action

Hello,

I've been testing XG for while now and it's a great product. So, I was playing around with QoS and set up a separate subnet to test bandwidth limitations per user, it works as it is supposed to but the issue kicks in when a user is limited to let's say 1Mbps and he starts downloading or uploading stuff, the latency for entire user pools goes to crap. I've researched this and this is a known problem with QoS setup whether it is used with Sophos or in general.

Attached is the screenshot, on the left-hand side you can see ping statistics from a user who is under Sophos QoS and on the right-hand side is the host computer pinging the same IP, as soon as I started speed test, you can see the latency spikes on the left-hand side  but right-hand (Host in my case) result doesn't seem to be affected as it is not rate-limited.

Currently, at home, I'm using pfSense and have setup traffic shaping which limits every single user to a certain bandwidth (20mbits) but there is no latency issue. My question is, is there any way in Sophos XG to rate limit every single client who is taking IPs from DHCP without having these latency issues?

Any feedback would be highly recommended!

Thanks