Thanks. I contacted support but figured it out in the meantime. My firewall was blocking NTP and Instant On access points seem to synchronize their clocks using NTP. Either access points would not send any usage data with unsynchronized clocks, or the cloud platform would drop usage data without feasible timestamps. In any case, no / empty usage statistics are displayed. Would be great if there was something mentioned about NTP in the documentation and even better, if an alarm would tell the user that the clocks did not synchronize.