I had the same issue with my QN75Q7FAM 2017 model receiving the update with the option turned of in settings.
The good news is that after owning this TV for over three years, I now have Dolby D+/Atmos bitstream passthrough! Not having that capability before the firmware update was literally the only complaint I had about this awesome TV.
I had previously complained quite loudly to Samsung about this oversight by their product team in not including Dolby Atmos capability in the original release. I'm very happy to see they've added it via a firmware update to the One Connect box.