Bar charts with influxdb creates only "spikes"

I am fighting a problem with the bar charts using influxdb as persistence service. I have a pump and the corresponding actor measures its power consumption by updating the power value based on changes larger than 5%. Plotting the time series as type Bar results in plots like

instead what I would like to get would look like
trying the type Line chart instead leds to
which is not what I am looking for too.

What have I missed ?

The line chart gives the game away that the charting service is “seeing” zeroes in your data. That might be a misinterpretation of absence of data, but first stop should be reviewing what is stored.

You have to select “connected” at the option “null value”

The data is sound. The pump was indeed turned off at about 18:00 and switched on again. So the line chart type looks more or less like I would expect it - it connects the data points with lines, fine. But the bar chart should keep the level until it changes with the next data point. But you are right, the screen shots are misleading. Especially as they show slightly different time slots.