NativeLink not working: Never saw 'Content Copied' or 'pasted from Safari'

[feifei-duan]

Describe the bug

I enabled the NativeLink on Branch dashboard for my Flutter project but NativeLink didn't work. And I never saw 'Content Copied' or 'pasted from Safari'. (Note that my IOS deeplink works fine in all other cases.)

I checked the box to enable NativeLink on Branch dashboard configuration page with audience set to 'All IOS traffic'. Then I tried to generate and click on a deeplink, but it doesn't show the NativeLink template view automatically. It was still showing the passive default deepview briefly and then automatically opened testflight because I set the Android redirect URL on Branch dashboard to be my testflight link (my app is only available on testflight).

Then I tried to manually enable the NativeLink template deepview using branch dashboard deepview manager by toggling the 'enabled' button. Now after clicking on the deeplink, I can see the NativeLink template view getting displayed. But after I click on the 'Get the app' button, it didn't show 'Content Copied' as what was described on Branch documentation. It did redirect me to Testflight. After I install the app, I also didn't get any prompt like 'pasted from Safari' as suggested in Branch documentation. After opening the app, FlutterBranchSdk.listSession().listen receives is_first_session: true, clicked_branch_link: false. Also tried using getFirstReferredparams but got an empty result.

Steps to reproduce

1. Make sure to use an IOS device (15+) with Safari brower as the default brower, and with icloud + and private relay enabled.
2. Make sure the app is not installed.
3. Make sure no deepview is manually enabled on branch dashboard deepview manager.
4. Check the box to enable NativeLink on Branch dashboard. Set the audience to All IOS traffic.
5. On branch dashboard, set the Android redirects when app is not installed to be a custom URL. In my case, I used the testflight link of my app (https://testflight.apple.com/join/...) on the branch dashboard as my app is only available on testflight.
6. Generate a short link using FlutterBranchSdk.getShortUrl(...) from a different device. Copy and send the deeplink on iMessage.
7. Click on the deeplink on iMessage with Safari as the default brower and with private relay enabled.

Expected behavior

I expect that I would be able to receive the deeplink params on the first app install (If the private relay is off or if I were using Chrome, I was able to receive the deeplink params on the first app install).
I also expect I would see 'Content Copied' or 'pasted from Safari' as described in branch documentation.

SDK Version

flutter_branch_sdk version: 8.2.0, which calls this NativeSDK

XCode Version

Xcode 15.2 (Flutter version: 3.24.3)

Device

iPhone 8 and iPhone 11

OS

16.7.10 and IOS 18.0

Additional Information/Context

Initially filed the issue on Flutter Branch SDK git repo RodrigoSMarques/flutter_branch_sdk#394
RodrigoSMarques responded that:
This package calls Branch Native SDK functions on each platform.
And pointed me to this git repo.

Thank you so much!