Inconsistent pn.state.busy when throttling is enabled globally

[TheoMathurin]

ALL software version info

Panel 1.4.0
Bokeh 3.4.0
In a server

Description of expected behavior and the observed behavior

I expect pn.state.busy to reflect the actual state of the app. With Panel 1.4.0, if pn.config.throttled is set to True, the busy parameter will be True as soon as a slider is moved, even if it's not released, and stay True forever, including in new sessions for the remainder of the app life cycle.

Note that this does not happen if throttling is disabled globally and the function is bound to slider.param.value_throttled.

Complete, minimal, self-contained example code that reproduces the issue

import panel as pn

pn.extension(throttled=True)


def synced_spinner(value):
    return pn.indicators.LoadingSpinner(value=value)


slider = pn.widgets.IntSlider(name='Slider', start=0, end=1)
text = pn.bind(lambda x: f'Value of slider is {x}', slider)
spinner = pn.bind(synced_spinner, pn.state.param.busy)

pn.Row(pn.Column(slider, text), spinner).servable()

Stack traceback and/or browser JavaScript console output

No error in python or javascript

Screenshots or screencasts of the bug in action

[philippjfr]

Strangely I was able to reproduce this once, and then never again.