This is not necessarilly Piggys fault. I have an eva meter-reader myself and a two weeks ago I experienced during an update that it stopped reporting power to Piggy for a long time, which could also be read from the logs of the eva meter reader which stayed unchanged for an hour before the power jumped up after two hours.
If you download the test version of Piggy you will find a graph in the front page in the settings dialogue. You will be able to pinpoint the exact hour the problem occurred here. You can take a snapshot of the graph and check it against the energy meter graphs from my.homey.app (missing data from this graph will just behave as a straight line) … however you need to check this within 24 hours after the error or homey loses its log and goes to 1 hour granularity, which is too coarse to check if this was the cause.
Anyways. In the new piggy graphs, if a loss of power data is detected piggy will mark its own graph as red. I will however improve this detection soon because it’s not optimal. You can track this here.
