Slow WAN speeds on older Ipads using DPSK

[itdude]

We are utilizing Ruckus internal DPSKs on our wireless network, however, we have run into an extremely unique scenario that only seems to be affecting older iPads. 

Virtual Smartzone Controller Version: 6.1.1.0.959

R550 AP version: 6.1.1.0.1322

We have several VLANs created for our clients and group DPSKs that, when authenticated, places them on a specific VLAN. When an older iPad is connected, it has no issues connecting to the WLAN and has internet access, however, the speeds are less than 1Mb. We tested to verify there was no other internal misconfiguration by connecting a newer iPhone to the same network (VLAN) with the same group DPSK and the speeds were working as anticipated, roughly 30-40Mb.

This is where it starts to get weird. If I take the same VLAN that the group DPSK was placing them on and create a new traditional WLAN with a WPA-2 key (no DPSK) and connect the older ipad, it works fine. That being said, we also have the original VLAN that was in use before we migrated to Ruckus setup with a DPSK and tested with the older iPad and it works correctly on that. 

So you might be able to see my dilemma. I have listed the scenarios we've tested with the older iPad and what the outcome was.

1. Original VLAN with a DPSK - 30-40Mb speeds
2. Original VLAN with a WPA-2 Key - 30-40Mb speeds
3. New VLAN with a DPSK - less than 1Mb speeds
4. New VLAN with a WPA-2 Key - 30-40Mb speeds 

After all my testing, I'm not really sure if its related to the DPSK since it works using one of our older original VLANs, but at the same time it doesn't work with a new VLAN using a DPSK. That led me to believe it was related to an internal networking issue with the new VLAN, however when using the new VLAN with just a WPA-2 key, it works correctly. So, I'm kind of stuck in the middle not really knowing where to go from here. Has anyone else experienced similar issues?