anybloodyname

Hi Frazer that's sorted it mate, it was taking off the sharing excess that fixed it, haha the one thing I didn't try!  :-)
getting completely solid pings now with no jitter whatsoever, I don't know what to allocate the PS4 but ill probably keep it at 40% as its working perfect now.
Thanks again mate, great that you guys gave the DumaR1 users the upgrade to dumaOs on the old hardware, top guys.

Hi Frazer that's sorted it mate, it was taking off the sharing excess that fixed it, haha the one thing I didn't try!  :-)
getting completely solid pings now with no jitter whatsoever, I don't know what to allocate the PS4 but ill probably keep it at 40% as its working perfect now.
Thanks again mate, great that you guys gave the DumaR1 users the upgrade to dumaOs on the old hardware, top guys.

It sounds to me most likely that you have Anti-Bufferbloat set to apply only when High Priority Traffic is detected, is that right? If so change this to always. Also under bandwidth allocation if you want to ensure a device only sticks with how much bandwidth you allocate it untick share excess for download/upload. Let us know how that works out. 
Also have you added your PS4 manually to Traffic Prioritization? If so remove it and just enable DumaOS Classified Games as it encompasses the console.

Good job guys this product really has evolved into a premier piece of kit, nice one. Its come a long way since the first firmware!