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If you still want to file a bug report, please make sure to fill in all the details below and provide the necessary information.
NOTE: PLEASE ONLY REPORT A SINGLE BUG USING THIS TEMPLATE.
If you’re experiencing multiple issues, please file a separate report for each.
Bug Description
1. Summary
When instantiating two MMKV instances with separate ID strings, both instances connect to a single dataset instead of having separate datasets. We use the Braze SDK which uses MMKV, so we’re unable to use MMKV at all inside our app code.
App Name: Fubo
App Link on Amazon Appstore (found through Developer Console → Actions column in App List → View on Amazon.com):
Bug Severity
Select one that applies
- Impacts operation of app
Blocks current development- Improvement suggestion
- Issue with documentation (If selected, please share the doc link and describe the issue)
- Other
2. Steps to Reproduce
Install “@amazon-devices/react-native-mmkv”: “~1.0.2”
I commented out the mmkv initialization in the Braze SDK before running this.
Create two MMKV instances with different ids
Perform some basic read and write operations to observe both instances share the same dataset.
import { MMKV } from '@amazon-devices/react-native-mmkv'
const store1 = new MMKV({ id: 'store1' })
const store2 = new MMKV({ id: 'store2' })
console.log('setting key1 to value1 in store1')
console.log('setting key2 to value2 in store2')
store1.set('key1', 'value1')
store2.set('key2', 'value2')
console.log('store1 keys:', 'expected:', ['key1'], 'actual', store1.getAllKeys())
console.log('store2 keys:', 'expected:', ['key2'], 'actual', store2.getAllKeys())
console.log('store1 get key1:', 'expected:', 'value1', 'actual', store1.getString('key1'))
console.log('store2 get key2:', 'expected:', 'value2', 'actual', store2.getString('key2'))
console.log('store1 get key2:', 'expected:', 'falsy', 'actual', store1.getString('key2'))
console.log('store2 get key1:', 'expected:', 'falsy', 'actual', store2.getString('key1'))
console.log('setting key1 in store2 to foobar')
store2.set('key1', 'foobar')
console.log('store1 get key1:', 'expected:', 'value1', 'actual', store1.getString('key1'))
3. Observed Behavior
Explain what actually happened, noting any discrepancies or malfunctions.
Both instances are connected to the same dataset. Writing to one store affects what’s read from the other store.
🪵 setting key1 to value1 in store1
🪵 setting key2 to value2 in store2
🪵 store1 keys: expected: key1 actual key2,key1
🪵 store2 keys: expected: key2 actual key2,key1
🪵 store1 get key1: expected: value1 actual value1
🪵 store2 get key2: expected: value2 actual value2
🪵 store1 get key2: expected: falsy actual value2
🪵 store2 get key1: expected: falsy actual value1
🪵 setting key1 in store2 to foobar
🪵 store1 get key1: expected: value1 actual foobar
4. Expected Behavior
Describe what you expected the SDK to do under normal operation.
Stores should have separate datasets
4.a Possible Root Cause & Temporary Workaround
5. Logs or crash report
(Please make sure to provide relevant logs as attachment)
For crash issues, please refer this guide for faster troubleshooting: Detect Where the App Crash Originates | Design and Develop Vega Apps
-
For issues with Kepler Studio Extension, please share log files from below folders:
~/.vscode/extensions/amazon.kepler-extension-<version>/ExtensionLogs ~/.vscode/extensions/amazon.kepler-ui-extension-<version>/ExtensionLogs
6. Environment
Please fill out the fields related to your bug below:
-
SDK Version: 0.20.3207
-
App State:
Foreground -
OS Information
Please ssh into the device viakepler exec vda shelland copy the output fromcat /etc/os-releaseinto the answer section below. Note, if you don’t have a simulator running or device attachedkepler exec vda shellwill respond withvda: no devices/emulators foundsh(com.amazon.dev.shell):/$ cat /etc/os-release NAME="OS" OE_VERSION="4.0.0" OS_MAJOR_VERSION="1" OS_MINOR_VERSION="1" RELEASE_ID="10" OS_VERSION="1.1" BRANCH_CODE="TV Ship" BUILD_DESC="OS 1.1 (TV Ship/4446)" BUILD_FINGERPRINT="4.0.184842.0(3072cab629675a74)/4446N:user-external/release-keys" BUILD_VARIANT="user-external" BUILD_TAGS="release-keys" BUILD_DATE="Sun Nov 16 06:26:48 UTC 2025" BUILD_TIMESTAMP="1763274408" VERSION_NUMBER="1001010444650"
7. Example Code Snippet / Screenshots / Screengrabs
Include any relevant code or component setup in React Native that can help reproduce the bug.
See section 2
Additionally please provide the following if possible
Provide Screenshots / Screengrabs / Logs. Please include as much information as you can that will help debug.
<!-- Answer here if applicable -->
Additional Context
Any Additional Context you would like to provide?
Add any other relevant information, such as recent updates to the SDK, dependencies, or device OS that may affect the bug.
Using @braze/kepler-sdk: 0.2.0 downloaded from https://community.amazondeveloper.com/t/vega-supported-libraries-and-services/1552#p-3000-third-party-services-4