c9800 WLC sends RADIUS accounting update messages too frequently to ISE

[robo0003c]

WLC C9800-40-K9 on 16.12.1

We are seeing a lot of alarms in ISE for "12929 NAS sends RADIUS accounting update messages too frequently". The NAS is a 9800 WLC and the clients are mainly phones on our eduroam SSID. On the old 5508 controller there is no issues.

What steps can I take to understand why these accounting messages happen to frequently? We have the following accounting config:

aaa accounting identity XXX start-stop group XXX
...
radius-server attribute wireless accounting mac-delimiter hyphen
radius-server attribute wireless accounting username-delimiter none
radius-server attribute wireless accounting username-case lower
radius-server attribute wireless accounting call-station-id ap-macaddress-ssid
radius-server attribute wireless accounting callStationIdCase lower
...
wireless profile policy eduroam
 accounting-list XXX

We are also running "radius-profiling" as well as " dhcp-tlv-caching" and "http-tlv-caching"

ISE alarms:

[marce1000]

 - You will find useful info from this thread and it's sub-threads :

                      https://community.cisco.com/t5/policy-and-access/ise-2-1-12929-nas-sends-radius-accounting-update-messages-too/td-p/3314699

 M.