_time field sometimes off when using aggregateWindow()

I get sensor data every 10 seconds. When using aggregateWindow as shown below, I would have expected the “_time” field to stay the same over the 10 seconds period until the new data is available, however, if I submit the same query multiple times within this 10 seconds window, the “_time” field sometimes changes to some unexpected odd numbers and on the next query it is back to normal. Why?

from(bucket: "sensor")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_field"] == "255/0/0")
  |> aggregateWindow(every: v.windowPeriod, fn: median, createEmpty: false)

How _time is expected:

How _time looks on some queries:

Hello @bado,
Hmm I’m not sure that feels like a bug.
Could you please create an issue here?

Thank you!

Hallo @Anaisdg,
Submitted - Issue