Ecowitt Issues

So, if you are using Wifi, the MAC is different than the one that it shows in the ecobee app. The ecobee app ONLY shows the MAC of the Ethernet gateway and the Wifi one is slightly different. So, if you have it set up by MAC in the preferences, then that is most likely the issue.

Post a screenshot of the preferences (mask the MAC except for the last two digits) as opposed to the Syslog Error message (also mask any MAC's except fot the last two digits). If you have the preferences set by IP, this should also shed more light on the subject.

But, if you did like I (and others did) and used the MAC in the Ecowitt app, that was your mistake (tongue in cheek) as their app only gives the MAC of the Cabled gateway and not the wifi (even if that is what is connected)

The logs are telling about this issue, and it has happened more than once (to me as well as others). You need to update the preferences in the parent device of your Ecowitt device (gateway) to use either the IP or the MAC listed in that Syslog error.
[RE-RELEASE] EcoWitt and Wittboy Weather Stations And Sensors (Local) - #1594 by tray_e?

Note that MY preference indicate a MAC ending in 40, but the app indicates my MAC ends in 43. 40 is what the actual MAC is for the Wifi Adapter