I recently switched back to the Google Messenger app on my phone (Nexus 6p), and have a custom notification for new messages set in the app. However, any time I get a new sms/mms, first the system wide default notification sound plays(which is different from what I have set in Messenger), and then the custom notification sound I have set in the app plays. Any idea why this is happening, and how to go about fixing it?
Edit: thanks for all the help, but I just rebooted my phone, and now everything is working perfectly again.