Threshold helper with ranges - is this a bug or my misunderstanding?

When you add a Threshold helper, the help text says “Both lower and upper limit configured - Turn on when the input sensor’s value is in the range [lower limit … upper limit].”. I presume the reverse of this is true - if the monitored sensor strays outside the range, the threshold sensor should turn off. But I’m not seeing this exact behaviour. A few screenshots:

First when the monitored sensor is in range:

Now with it on exactly the lower range:

Now with it below the range:

So far, so good. But now with it back at the lower range limit:

Why does it say the sensor is still below, and the threshold sensor is still off? I wouldn’t think a particular value can sometimes be below, and sometimes be in-range.This seems to be a problem whenever you cross a range boundary, either upper or lower. Or am I misunderstanding something fundamental? Thanks for any comments.

Can anyone help here?