If you use a Slider and set onValueChanged to go to UdonBehaviour.SendCustomEvent, it will always send 0 even though your custom event implemented a float parameter.

The reason for this is that SendCustomEvent takes a string parameters, not a float parameter, and is therefore shown under the static section, and not under the dynamic floats section. As a result, we can't actually get the float value from the callback, leaving the Slider onValueChanged event basically useless if we want to know what value it is.

A workaround would involve passing in the Slider as a public variable, then using the callback with SendCustomEvent, and grabbing the value from the Slider component.

Not entirely sure of a good solution to the problem as SendCustomEvent would always require a string parameter so it knows where it's going. Even if custom parameters were added so you can call the function with parameters, this probably still wouldn't fix it

Not sure whether you can consider this a bug or not due to the cause, but it kinda effectively behaves like a bug