FloatProperty() how can I assign a value after the update= has finished

I have a slider linked to a custom property.But in order for the update= function to work the way I want it,it needs the FloatProperty to be reset to a given value,every time the user stops dragging the slider.

How can I do it,and is it possible at all?

I tried to add this at the end of the update= function but then blender was struggling between the user input(holding the mouse key on a specific value) and the function which is updating and on every update it tries to reset it to the value I want.So that’s out of the question.

This should not be possible, as the reset of the property after the update function would be another assignment of the property, and trigger another update, which would again reset, which would again update,… Seems like you would be running into an endless loop

well as I said I did it in the update function…it was not an endless loop…but it made blender update really really really slow.Once the slider was released it was fine. So even though it worked…somehow.it’s obviously not the way to go. Again my point is to have the value return back to a given amount after the mouse release of the slider.
I was thinking of making a Modus Operator to track for mouse movement,and have the FloatProperty inside it.But I have no idea how to link the slider with a property inside the modus Operator.