Looking at your post again – there is some sort of problem/feature in HA in general that means that the statistics card does not plot sensors which has states which typically increase but sometimes reset – e.g. exactly the output of the utility_meter.
This is somehow related to the state_class attribute for sensors – if it is “measurement”, it can go up/down without problem. If it is total_increasing, it should never go down, so maybe the card does some assumption on the data and fails to plot it. There is also a “total” state class, which can go down on resets and this should be the class of your utility_meter really, but this doesn’t seem to help.
Personally, I am not quite sure what the statistic graph card really is trying to do by differentiating between the different type of data. Data are data…