HP Unified 850 Controller L3 Roaming

[AJ6]

Hi,

I would like to know about L3 roaming in 850 controller where i have the following setup:

we have multiple wireless services with the same SSID but diffrent VLANs.

each wireless serivice is mapped to a specific AP group based on the AP location.

In a lounge we have two diffrent areas with diffrent wireless services. Initialy we kept 1 wireless service for both the areas anc the clients were able to move without any issue. now after changing to diffrent service we have the same SSID but with the diffrent VLAN. 

Clients are getting disconnected 

i would like to know how can we acheive the roaming between the areas and if we need a set of configuration to be done on the controller.