I put both hosts into DEBUG mode and here's a snippet from the Server side during a Webex hangup.
longrow = client
milo = server
[2017-07-26T14:00:20] NOTE: client "longrow" is dead
[2017-07-26T14:00:20] INFO: jump from "longrow" to "milo" at 1280,720
[2017-07-26T14:00:20] INFO: entering screen
[2017-07-26T14:00:20] DEBUG: active sides: 2
[2017-07-26T14:00:21] NOTE: accepted client connection
[2017-07-26T14:00:21] DEBUG: received client "longrow" info shape=0,0 1920x1080 at 13,0
[2017-07-26T14:00:21] DEBUG: active sides: 2
[2017-07-26T14:00:21] NOTE: