I was away for 30 hours or so, although I accessed my Mac with screen sharing a few times (did not go to Indigo). About 8 hours after my last access, I found in the Indogo log:
Nov 26, 2020 at 5:57:15 PM
Received INSTEON "Thermostat-Living Room" temperature changed to 64.0
Nov 26, 2020 at 5:58:22 PM
Received INSTEON "Thermostat-Living Room" temperature changed to 65.0
Nov 26, 2020 at 6:02:09 PM
Received sleep notification from system
Closed connection to PowerLinc 2413U
From there on, all commands were null because my 2413U was offline. I attempted to turn on my lights with the iPhone client and, while it seemed to work from the iPhone, none of the lights went on. When I got to the Mac, it was not sleeping. But I went to Indogo and I watched as the 2413U came back awake without my doing anything except accessing the Indigo client. From the log:
Sent (offline) "Back Porch Lights Main" on to 100
Nov 26, 2020 at 10:45:17 PM
Received awake notification from system
NuVo Grand Concerto Just added: Z11 to zonedev
It would be great if the system did not randomly go to sleep or if the iPhone client would wake it up. This seems to be a new problem with Bog Sur, although something similar happened once or twice in the past 3 years with previous operating systems.