That’s a little disingenuous. The logs show that for much of that time, they were unable to connect to WiFi. That they were later able to connect indicates to me that something else was going on during that period, not that the IoTaWatt just decided to stop posting to influx for no apparent reason.
I don’t like like to guess. If you want me to look at the failure on IoTa2, you will have to provide the log for IoTa2.
In general, these problems that you have been having with influx turn out to be problems with the WiFi or the influx system. In the case of IoTa1 here, when the WiFi is apparently restored on 3/13 10:19 after about a 24 hour outage, influxDB is not responding accurately to the last post query. It looks like something may have changed with influx, but I have such little information that I can only speculate.
There are a lot of components in your system. The IoTaWatt are just one. There is also the WiFi and the influx system. When both IoTaWatt stop posting at the same time, that suggests very strongly to me that the problem is in one of the other components. I have a few IoTaWatt here that post to a local influx on a RPi. They work flawlessly day-in and day-out for the past year. There are no other outstanding problem reports with influx.
This is like the old story where a guy is looking for something under a streetlight at night. A passerby asks what he is looking for and where he dropped it. The guy responds that he dropped it across the street. When asked why then is he looking for it here, he answers “because the light is better here”. I think you are looking in the wrong place for this problem.