In your config you still use the rpigpio factory.
Have you tried changing this to lgpio.LGPIOFactory, like described in the linked thread?

@AlvinSchiller

I have uninstalled rpigpio and installed lgpio:

systemctl --user stop jukebox-daemon
source .venv/bin/activate
pip uninstall rpi-gpio
pip install rpi-lgpio
systemctl --user start jukebox-daemon

I also tried alternative factories in gpio.yml:

pin_factory:
#  type: rpigpio.RPiGPIOFactory
  type: lgpio.LGPIOFactory

... which does not change the behavior at all.

When I close the button then it actually plays the song without jittering / oscillation.

To my understanding the GPIOs are digital inputs so there should not be a threshold issue. It feels however as if the GPIO would be activated by some noise and a state that should be LOW is sometimes read as HIGH.

After quite some fiddling around I think I found a way to get it working - although not fully sure if this is how the button is intended to work.

I connected the button to pin GPIO_17 and 3V3 (external 1kΩ resistor). When I then modify the gpio.yml like so:

pin_factory:
  type: lgpio.LGPIOFactory
input_devices:
  TogglePlayback:
    type: Button
    kwargs:
      pin: 17
      pull_up: 
      active_state: true
    actions:
      on_press:
        alias: toggle

the button works as expected. Note that the pull_up is intentionally set to none to disable it.