There does appear to be an issue with LowestLow when the range is 0. I added a couple of plots to see, the blue line should have gone to 0 after the 0 range bar. Because 0 can mean that we have no data, it is sometimes ignored. In a datalist that makes sense, but does not help in this case. We’ll need to get that looked at.
In the mean time, the simple way to get around this is to add 10 to the range.
RANGE = HIGH()-LOW() + 10;
It’s not “correct” but gets you the results you are after.