App Submission Rejected - Unable to replicate bug

Apple rejected my app store submission (first submission of this app) with the following comment:

Issue Description: The app exhibited one or more bugs that would negatively impact App Store users.

Bug description: The app opens to a black display

Steps to reproduce bug: Launch app. 

Review device details:

- Device type: iPhone 13 mini 
- OS version: iOS 17.4.1

Next Steps: Test the app on supported devices to identify and resolve bugs and stability issues before submitting for review.

No other details given on specific scenarios. No logs provided. We asked for more info but they refused to help any further.

I just so happen to have that exact device (iPhone 13 mini), so I updated it to the iOS version that was giving problems. But no matter what I do, I cannot replicate this bug. I tried via TestFlight and via Xcode, I tried deleting and reinstalling the app, and I tried restarting my phone between installs. I tried launching the app while on airplane mode. I never got this "app opens to a black display" issue.

What else can I try to replicate this bug?

The app is built with Unity 2021.3.19f1.