Zero4U wifi interference despite using ferrite ring

Purchased the Zero4U USB hub for the Pi Zero W (https://shop.pimoroni.com/products/zero4u) and as expected it shipped with the ferrite ring (http://www.uugear.com/portfolio/is-zero4u-compatible-with-raspberry-pi-zero-w/). Put the product together as instructed and although it worked perfectly on the first boot I quickly noticed that the USB hub reboots if the wifi on the Pi Zero is doing anything other than stable data transfer I.E. searching for or joining a network for example.

I have played around with the placement of the ring to see if that had any benefit but it hasn’t seemed to help.

I really like the Zero4U hub and I don’t want to have to return it, any ideas?