I was experiencing an issue with the in-app audio whereby I couldn't hear it at all. I contacted the support team and they advised me to close the app, switch off bluetooth, clear the app's cache and reopen it. This appeared to solve the problem but only temporarily... now I have to do this each time I want to use the app - it's incredibly annoying. Instead of putting the onus on users to navigate around the issue, it would be great if the developers could fix it.