Generally, eARC is a decent enough concept. Unfortunately, it doesn't always work as expected, which can cause some headaches.
The golden rule is to simply buy an external streaming device, like an AppleTV 4K, a Roku Ultra, or a FireTV Cube. This will give you a faster and often better streaming experience than the built-in apps on the TV itself. It keeps you from having to rely on the TV as the hub to your audio and puts it back into the AV receiver where it belongs.
SOURCE-->AV RECEIVER-->SPEAKERS
SOURCE-->AV RECEIVER-->TV