I've used Macbooks since 2009 and have never once had the problem I've encountered tonight. I ran a malware scan (not sure if that's connected, that's just when it started) and now I can't stop Music from opening and automatically playing whatever playlist is selected. More bizarre is the fact it happens more often every time I close it, and at times it even seems the position of my laptop is a factor, while at other times, it doesn't do anything. Definitely the weirdest thing I've ever had happen with a Macbook, especially now that, since I decided to post something about it here, the issue stopped happening. For the moment, at least.
All the other posts I could find with steps to solve this wacko problem are way out of date by now (the newest was from Jan, 2018), so hopefully this at least gets a new guide to fixing the issue out there.