Meizu MX4 isn't playing sounds any more

Initially I stopped getting notifications for Telegram and text messages. Then I realised a few days later that I had missed a lot of phone calls, at which point I realised I hadn't been getting audible notifications for these now either. Then about a week ago my alarm clock didn't wake me up like it had the day before. I then realised I couldn't get my phone to play any sounds at all, including youtube videos or radio.

Any ideas what could have caused this? I've recently replaced my battery, and dropped my phone. Any ideas for what I could try to trouble shoot or get around it? I've updated ubports to the latest version.