Issue with Grafana Override Persistence in InfluxDB for Summing Two Inverters' Power Output

Hello, I’m logging the data from my PV system into an InfluxDB and would like to visualize it with Grafana 10.1.4. All runs on an RaspberryPI4.

My problem: I have two inverters and would like to create the sum of their power outputs. This works perfectly in InfluxDB, and in the explorer, it only shows me the sum:

from(bucket: "smarthome")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_measurement"] == "power-stats")
  |> filter(fn: (r) => r["_field"] == "Leistung_WR1" or r["_field"] == "Leistung_WR2")
  |> aggregateWindow(every: 1m, fn: mean, createEmpty: false)
  |> pivot(rowKey: ["_time"], columnKey: ["_field"], valueColumn: "_value")
  |> map(fn: (r) => ({r with _value: r.Leistung_WR1 + r.Leistung_WR2}))

Now, when I insert this into Grafana, it shows me the values for Inverter1 (WR1), Inverter2 (WR2), and the sum. I use the Override → Hide in Area, so it shows only the sum, but when I go back to the dashboard and it refreshes, it somehow overrides the override, and I see the old display with the three values.

Does anyone have advice?