Programmatically changing a slider value

  Hi,

there are several occasions in which I programmatically change the value
of a slider by calling (setf (range-slug-start ...) ...): just before
the interface is display to initialize it, from a button's callback,
etc.

In one instance, I switch to the REPL which is in another tab (so the
interface is hidden), call a function that changes the range slug start
value, and switch back to the interface. Now, the slider is wrong (see
attached picture): the blue bar is correct, but the slug remains at the
old position. This is on Mac with PE. Is this a bug or am I doing it
wrong ?

Thank you!


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