Ok, well so far so good. I've not been on my phone as much as I usually am, but so far everything is fine. I went into my Settings - Device Care - Battery - it says 'Usage by apps', and when you tap on one, depending which one it is, it gives you the option to 'Put this app to sleep when not in use'. So, I did that with all the apps that I don't need constantly running in the background. For example though, I left my Fitbit on because that app doesn't need to go to sleep unless it's on the charger. I ALSO disabled everything Bixby, so it could also be that. I'm still going to give it more time though, but so far so good!