If you are using the Moonlight Embedded client on a Raspberry Pi 4, I would for sure try the "QT" version, it's available here.
Otherwise, there are some clients that work on older Raspberry Pis. For example, Parsec works really well. With a stable enough Wi-Fi connection, Steam Link works well too. If you're wondering, yes, it still is possible to use Moonlight Embedded with OpenStream, but you're limited to 720p. I tried changing the resolution, but it usually froze or crashed. (most of the time, the display and the text were pink)