My setup includes a Caroline DUT and two Cisco 3800 series APs with the two APs placed right next to each other and the DUT about a meter beneath the APs. The APs are both on the lowest power level possible and the DUT is running WiFi Analyzer (to trigger constant background scans).

Occasionally, upon initial connection to the network, the DUT will begin ping-ponging between the APs rapidly (up to several roams a minute). net.log indicates that the signal levels perceived by the DUT from a single AP varies from ~-50dBm to -65dBm between scans (probably around 10 seconds apart), even though the DUT and the APs are completely stationary the whole time.

I've used WiFi Analyzer from my Pixel to look at the signals while they were fluctuating on the DUT, but the Pixel reported them as completely stable. I haven't done much other testing besides this since the problem stopped occurring after an hour or so, and I haven't been able to reliably reproduce it since.

It looks like crbug/832186 might be the same issue.

net.log: https://drive.google.com/open?id=1crTQpGLCeFiNC5h1XtfGNjDLvJd2l0LP