REASON FOR INTERMITTENT CONNECTIVITY
Plume Networks optimize on a regular basis to ensure a location is functioning optimally. During this process we may change channels on either 5Ghz or 2.4Ghz, or both bands based on various factors. Ecobee fails to switch to the new channels after optimization. This causes the device to disconnect and at times, fail to connect back until Ecobee is manually reconnected to the Wi-Fi network.
We have escalated the matter to Ecobee, who have released firmware to address the issue.
Ecobee has released a new firmware version 184.108.40.206 for their Ecobee 4 devices. If you have Ecobee 4, then please ensure you are running this firmware at the minimum to mitigate the issue.
Ecobee has released firmware version 3.70.992 for their Ecobee 3 devices that addresses the issue with channel changes. If you have Ecobee 3, then please ensure you are running this firmware to mitigate the issue.
Ecobee has confirmed that firmware 220.127.116.111 for Ecobee 3 does not contain the channel change fix, but are working on a newer firmware that will address the issue.