Using build variables in manifest shows cannot find symbol error in some places but not others

This is more of an annoying one more than anything, as my project seems to build ok, but I'm trying to use the ${applicationId} build variable in AndroidManifest.xml, and it works fine with no warning or errors in some places, like android:label="${applicationId}", but it returns warnings/errors in the following :

  <activity 
         // various properties etc.>
        <intent-filter>

                <data android:scheme="${applicationId}.myContinuedString" />
        </intent-filter>
  </activity>

This shows as a red warning ("Cannot resolve symbol 'applicationId'"), but the app otherwise builds fine. But it won't go away. And I've tried the following:

• Invalidate cache/ restart
• Clean, rebuild
• Switching to different build variants
• Manually adding a manifestPlaceholder in build.gradle
• Moving ${applicationId} to different locations in the manifest. As mentioned earlier, works in some places, like android:label but not in this <data android:scheme tag.

Any guidance as to why it's doing this?