Try wiping the cache partition on your phone and that should resolve the issue. To do this, just search 'how to wipe cache partition S8' and you should find what you are looking for 😁. Hope this helps! 🤓
It unfortunately didn't work for me 😞 but I noticed that when the phone has recently been turned on it works fine switching when the on and off button is pressed but once I unlock it and go back to the lock screen it doesn't work any longer
