To reproduce:

1. Download and open attached "AndroidRegionTest.zip" project.
2. Make sure that scripting backend for the project is set to mono.
3. Build and run the project for any platform which supports mono scripting backend.
4. Examine provided logs.
5. Notice the output of RegionInfo class.

Expected result: The following information is returned:
--ISOCurrencySymbol: USD
--CurrencyEnglishName: US Dollar
--CurrencyNativeName: The requested feature is not implemented.
--CurrencySymbol:

Actual result: The following information is returned:
--ISOCurrencySymbol: US Dollar
--CurrencyEnglishName:
--CurrencyNativeName: The requested feature is not implemented.
--CurrencySymbol: USD

Reproduced with: 2018.1.0b1, 2017.3.0p1, 2017.2.1p1, 2017.1.3f1, 5.6.5f1, 5.5.6f1.

Devices under test:

Xiaomi Mi 4i, OS:5.0.2, CPU:arm64-v8a, GPU:Adreno (TM) 405,
Build:Xiaomi/ferrari/ferrari:5.0.2/LRX22G/V8.5.3.0.LXIMIED:user/release-keys

Google Pixel, OS:8.0.0, CPU:arm64-v8a, GPU:Adreno (TM) 530,
Build:google/sailfish/sailfish:8.0.0/OPR3.170623.008/4294783:user/release-keys

iPhone 7 plus 10.3.2

Notes: Tested and reproduced with Standalone, Android and iOS builds with Mono scripting backend. Built with IL2CPP returns correct result. WebGL build returned correct results.

Note: Fixed for .NET 4.6 only!
Fixed in: Unity 2018.2.0a7