Hi Christiaan,
What is the Radio status for the APs which are placed on Visualrf? Does it shows "ok" or "error" state?
Could we try to manually poll Airwave database from visualrf using the below URL,
https://<amp_server_ip>/visualrf/poll_aps_now.xml
Note: Replace <amp_server_ip> with your Airwave server IP
Regards,
Vishnu