The issue begun the moment the iOS 13.5.1 became available. What it does is drastically increase the amount of power that the phone requires when using the Apple Music app - up to 80% of battery's power capacity.
Apple has yet to officially acknowledge the problem, much less share a solution. According to some people online, there are some actions that help with the issue: hard-resetting the phone and uninstalling Apple Music among them.
Alright, children, the time for speculation is over. Galaxy Note 20 will be released on August 5