Changes Stop Emitting

### Issue
When waiting for changes, after a period of approximately 20 minutes change events stop emitting.

### Info
- Environment: Node.js 16.x
- Platform: Windows
- Adapter: leveldb
- Server: PouchDB via pouhdb-node

### Reproduce
Here's the code. It fires fine for all changes received once the app is started (it's an express web app) but after a period of approximately 20 minutes of inactivity the change event no longer fires and seemingly goes dormant:

global.db.changes({live: true, include_docs: true})

    .on("change", function(change)

        {   console.log("DB change: ", change);

        })

    .on("complete", function(info)

        {   console.log("Changes listener was cancelled: ", info);                

        })

    .on("error", function(err)

        {   console.log("Changes listener encountered an error: ", err);                

        })