MS Radius and CISCO WAP121 access points

Hi!

Cisco access points WAP121 are connected to Radius server (NPS Windows 2012R2). Authentification using domain accounts works fine, but there are strange values in logs. I can't find unique IDs for user sessions. They all are 00000000-00000000

<Acct-Session-Id data_type="1">00000000-00000000</Acct-Session-Id><Acct-Status-Type data_type="0">2</Acct-Status-Type>

Is it possible to fix it? 

For each AP (Radius client) on NAP server "Vendor type" parameter is set to Cisco.