That’s because it’s using an older Samsung Exynos 5300 modem from the Pixel 8 series, according to Android Authority, instead of the newer Exynos 5400 in the rest of the Pixel 9 lineup. It means you won’t be able to link with satellites for emergency SOS messaging or calls if you’re in an area without cellular coverage. Maybe take another phone on that long hike. The Pixel 9a is also missing AI features found in the other Pixel 9 phones.