Fix Shopify application issues.

I am looking for an expert website developer to work with on an ongoing basis to fix issues as they occur on our custom Shopify application. We hired a team through Freelancer previously to create a custom app for our Shopify website, but it occasionally has issues that we need help fixing. The first project we need help with is to fix a current issue happening with our custom Shopify app. It is an audio player app that allows customers to create custom playlists from our library of audio tracks, and customers are reporting that their playlists are stopping and not playing properly. We need a developer to look into this issue and let us know how to fix it. Thanks!