Have Arc, where's Atmos?

First, I’m happy with the Arc; it delivers great 5.1 Dolby Digital Plus surround sound, working with our Sony X950h TV’s eARC port (plus our Sub and rear One speakers). Ratings.com says that this Sony will pass through all flavors of surround signals, including Dolby Atmos. But I have yet to encounter the much ballyhooed Atmos. I’ve read that many Netflix shows include Atmos. I have revisited some of their most recent 5.1 DD+ original programming, on the assumption that if any shows would include Atmos, they would. I’ve streamed them both via my Roku box and via the Netflix app that’s native to the TV. In both cases, the S2 app confirms I’m getting a 5.1 DD+ signal, but there’s no evidence of Atmos. “Atmos” also doesn’t display in the app’s home-theater “room” setting. I’ve set all the TV’s HDMI ports to “enhanced,” as recommended. Am I missing something? Does anybody have thoughts re. why I don’t seem to be getting Atmos? It’s not mission-critical by any stretch of the imagination, but I’d love an answer.