Signature mismatch between apk & espresso apk when running tests on Browserstack automate

I've written a pipeline on Azure that builds our apk, builds the espresso test apk, signs them both with the Keystore that's located in secure storage, then uploads them to BrowserStack automate & executes the test. The issue occurs at the Builds dashboard on Browserstack where it says :

There is signature mismatch between application APK and test-suite APK. Package com.example.appName.test does not have a signature matching the target package com.example.appName. Please fix this, upload your app & test-suite APK and execute the test again.

Here's my.yml file:

pool:
  vmImage: ubuntu-latest

steps:
# download .jks file from secure files for signing
- task: DownloadSecureFile@1
  name: keystore
  displayName: 'Download keystore file'
  inputs:
    secureFile: 'appName.jks'

- script: |
    echo Installing $(keystore.secureFilePath) to the trusted keystore directory...
    sudo chown root:root $(keystore.secureFilePath)
    sudo chmod a+r $(keystore.secureFilePath)
    sudo ln -s -t /etc/ssl/certs/ $(keystore.secureFilePath)
  displayName: "Installing keystore file"

# build apk
- task: Gradle@2
  inputs:
    workingDirectory: ''
    gradleWrapperFile: 'gradlew'
    gradleOptions: '-Xmx3072m'
    publishJUnitResults: false
    testResultsFiles: '**/TEST-*.xml'
    tasks: 'assembleGoogleDebug'
  displayName: "Building default APK"

# Build test apk
- task: Gradle@2
  inputs:
    workingDirectory: ''
    gradleWrapperFile: 'gradlew'
    gradleOptions: '-Xmx3072m'
    publishJUnitResults: false
    testResultsFiles: '**/TEST-*.xml'
    tasks: 'assembleGoogleDebugAndroidTest'
  displayName: "Building test APK"

# sign the apks with the same signature
- task: AndroidSigning@3
  inputs:
    apkFiles: '**/*.apk'
    apksignerKeystoreFile: 'appName.jks'
    apksignerKeystorePassword: '***'
    apksignerKeystoreAlias: 'appName'
    apksignerKeyPassword: '***'
    zipalign: false
  displayName: "Signing APKs"

- task: BrowserStackConfig@0
  inputs:
    BrowserStackServiceEndPoint: 'BrowserStack connection'
  displayName: "Establishing BrowserStack connection..."

# Upload apk to BrowserStack
- task: BrowserStackAppUploader@0
  inputs:
    appPath: '/home/vsts/work/1/s/presentation/build/outputs/apk/google/debug/presentation-google-debug.apk'
    appCustomId: 'sport24'
  displayName: 'Uploading default APK to BrowserStack'

- script: |
   curl -u "name:key" \
   -X POST "https://api-cloud.browserstack.com/app-automate/espresso/v2/test-suite" \
   -F "file=@ /home/vsts/work/1/s/presentation/build/outputs/apk/androidTest/google/debug/presentation-google-debug-androidTest.apk"
   -F "custom_id=appNameTest"
   echo "triggering test" 
   
   curl -u "name:key" \
   -X POST "https://api-cloud.browserstack.com/app-automate/espresso/v2/build" \
   -d '{"app": "url", "testSuite": "bs://url", "devices": ["Samsung Galaxy S9 Plus-9.0"]}' \
   -H "Content-Type: application/json" 
  displayName: 'uploading test suite and triggering test'

# post test results
- task: BrowserStackResults@0

I'm signing both APKs with the same Keystore & the test class is located under com.example.appName/androidTest/ so I can't figure out what's causing the mismatch. Any ideas?

from Signature mismatch between apk & espresso apk when running tests on Browserstack automate