Thanks AW, I've looked at the metadata options and don't recognize anything that might help, but be sure i'm no expert on this terminology so it's even possible I've configured it wrong in the past.
In Tweaks I've now enabled keep service and use wakelock. I'll test later today.
If I have messed things up, is uninstalling and reinstalling (without loading my saved settings) the easiest way to start from scratch with default settings?