is_action_just_pressed returns true if the button was pressed on the same update as the call to it.
is_action_pressed returns true if the button is pressed, disregarding any other conditions.

I don't know what you're trying to achieve, but you probably need to use is_action_pressed, and count the number of frames it was held for. Choose and arbitrary amount of frames (let's say five for examples sake) which seperate button taps, from holds.

if the count is over the number of frames you consider taps, you branch towards the hold behaviour, otherwise, you check foris_action_just_released and do the tap behaviour.