Yes, but only when system audio is set to “Dolby Atmos” (requires HDMI to Atmos AVR).
Mobile devices default to stereo to save bandwidth. Casting to a TV may reactivate surround. netflix surround
What Surround Sound Formats Does Netflix Support? Netflix supports several surround sound formats depending on your subscription plan, device, and content: Yes, but only when system audio is set
Yes, but separately: “Netflix Spatial Audio” (available on Premium plan) works with any stereo headphones, simulating 5.1 or Atmos. It is not true multichannel but can be effective. and content: Yes