No,not necessarily. We need to make sure if handset supports this feature.
WPA Fast Handover is applied only to 802.1x and this will allow the WPA clients to use a pre-authorized PMK to reduce the handover interruption.
Make sure on handset increase the battery power to max, disable Power-save mode. You can refer to below link for VRD as well.
http://www.arubanetworks.com/wp-content/uploads/VoIPwMASAppNote-20120726.pdf
Please enable user-debug and show auth-tracebuf mac <mac address of the client> and post.
From configuration mode:-
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logging level debugging user-debug <mac address of the client>
Thank you.