I tried that. But its not problem of the Settings of audio sample rate. As you can see, the audio2face app starts freezing when its not focused in foreground. Check the video. There is literally problem when the app is in background. But this happens only with unreal. (The project in the right is clear project with your plugin, nothing else.) And when I focus back (the a2f app), it starts working fine.
I found something similar here Audio2Face2023.1.0 to UE get stuck