can't stop hyperion.ng instances

I want to stop/start latest hyperion.ng with a python script. Start is working but not stop.

LED_on = {"command":"componentstate","componentstate":{"component":"ALL","state":"true"}}

LED_off = {"command":"componentstate","componentstate":{"component":"ALL","state":"false"}}

response_LED = requests.post('http://192.168.50.9:8090/json-rpc', json=LED_on)

response_LED = requests.post('http://192.168.50.9:8090/json-rpc', json=LED_off)

System: Raspberry Pi4 with Raspberry OS Lite and Kodi 18.7, apa102, internal grabber
N.B.: hyperion.control is also not working

I could not found the reason why I can switch on but not off but I found another way which is also not bad. Every seconds I'm requesting the Kodi web server which player is running and if video or picture player ID is showing up, I switch hyperiond service on and if idle or audio playing, I switch hyperiond off. Additional benefit, it saves CPU if no hyperiond is needed (and I learned a lot). Python program takes <1% CPU (top).