The Google Pixel 4's Soli Radar feature is authorized for use in only certain geographies as it uses the 60 GHz frequency band. Those wanting to use the Motion Sense features can now do so irrespective of the region by taking advantage of a hidden debug feature. However, this requires unlocking the bootloader and enabling root access.
https://www.notebookcheck.net/The-Pixel-4-s-Soli-Radar-can-be-enabled-in-any-region-thanks-to-a-hidden-debug-feature.440988.0.html