YouTube is available in 2-channel only. During the phase testing, you had the Pioneer on PLII or Neo and that steered 2-channel out of phase information to the surrounds. That's how PLII and Neo work to simulate surround.
SPDIF raw is a bitstream for optical connections. HDMI raw is a bitstream for HDMI connections. Select HDMI raw. The Android box will send a bitstream to the Pioneer and the Pioneer will decode it into the correct format. The Pioneer may have some option you need to enable to make this happen.
DTS DRCscale is dynamic range compression. Your wife will love that. It limits dynamics so that all sounds don't exceed a normalized range. Good for relationships; terrible for audio.
Dolby sounds is a way to increase the volume of dialogue relative to other sounds.
You may also want to check if the Android box is on the latest version. Some manufacturers ship without full testing and follow up with new versions.
