I programmed several Watch buttons on SPA500 module and some buttons stay lit red even though the phones are not used. When pressing the button it does call the Vacant phone.
How can I fix the state to be correct and only be lit red when the corrsponding phone is used?
It should be working based on the config.
Could you try removing the button from the phone you are watching and readd it? Could you try removing the watch for that button and readding it?