Sync preferences are not saved during account creation on iOS

[jonalmeida]

Affected FxA versions:

• 1.302.1;

Tested Firefox version:

• 134.1;

OS version:

• iOS 18.1.1;

Prerequisites:

• Do not have an fx account created;
• Do not be connected to Sync;

Steps to reproduce:

1. Perform the sign up flow from Sync and select 2-3 sync options during creation;
2. Click on the hamburger menu option;
3. Click on the option that displays the email address from step 1;
4. Observe the Sync settings option;

Expected result:

• The selected options during account creation are on;

Actual result:

• All the sync options are off;

Additional notes:

• We are not able to find a pattern that triggers this issue, we are encountering it randomly;
• See attached media in FxA bug.

┆Issue is synchronized with this Jira Task

[jonalmeida]

This is an iOS bug - during the first sync the SyncParams.enabledChanges is always empty which leads to the list of ‘Choose what to sync’ options be turned off. Sync is working correctly, it’s the application side that needs to set the correct engines in the first sync. You can follow what Android does here: https://searchfox.org/mozilla-central/rev/4f5426084651871759f5346eb0ded2e9ac5326fd/mobile/android/android-components/components/service/firefox-accounts/src/main/java/mozilla/components/service/fxa/sync/WorkManagerSyncManager.kt#407