[Bug] 0.76 - border-radius with non-integer values causes faded bottom padding

Description

I have just updated to RN 0.76 and seeing some weird behavior with non integer values when applying corner radius. It creates a bottom padding that has a faded color.

Steps to reproduce

Create a simple view and apply the following values:

  return (
    <View className="h-full bg-indigo-900 p-4">
      <View
        style={{
          marginVertical: 400,
          borderTopLeftRadius: 10,
          borderTopRightRadius: 10,
          backgroundColor: 'white',
          padding: 14,
        }}
      />
    </View>

The output should look like this:

But instead it looks like this:

React Native Version

0.76.0

Affected Platforms

Runtime - iOS

Output of npx react-native info

System:
  OS: macOS 15.0.1
  CPU: (11) arm64 Apple M3 Pro
  Memory: 223.63 MB / 36.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.13.1
    path: ~/.local/share/mise/installs/node/20/bin/node
  Yarn:
    version: 4.5.1
    path: ~/.local/share/mise/installs/node/20/bin/yarn
  npm:
    version: 10.5.2
    path: ~/.local/share/mise/installs/node/20/bin/npm
  Watchman:
    version: 2024.10.21.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/osp/.local/share/mise/installs/ruby/3/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.0
      - iOS 18.0
      - macOS 15.0
      - tvOS 18.0
      - visionOS 2.0
      - watchOS 11.0
  Android SDK:
    API Levels:
      - "33"
      - "34"
      - "35"
    Build Tools:
      - 30.0.3
      - 33.0.0
      - 33.0.1
      - 34.0.0
      - 35.0.0
      - 35.0.0
    System Images:
      - android-33 | Google Play ARM 64 v8a
    Android NDK: 26.1.10909125
IDEs:
  Android Studio: 2024.2 AI-242.23339.11.2421.12483815
  Xcode:
    version: 16.0/16A242d
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 21.0.3
    path: /usr/bin/javac
  Ruby:
    version: 3.3.1
    path: /Users/osp/.local/share/mise/installs/ruby/3/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 15.0.0
    wanted: ^15.0.0
  react:
    installed: 18.3.1
    wanted: 18.3.1
  react-native:
    installed: 0.76.0
    wanted: 0.76.0
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: false
  newArchEnabled: false
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Stacktrace or Logs

*

Reproducer

https://github.com/ospfranco/border-radius-bug

Screenshots and Videos

No response

Start by running the linked border-radius-bug reproducer on iOS with React Native 0.76.0 and compare its output with the expected and actual screenshots. Trace the iOS rendering path for non-integer border-radius values, then verify that the faded bottom padding no longer appears while the supplied example still renders correctly.