Same issue over here: app getting rejected because of the a timeout during login.
It's an app built with Ionic framework and I didn't have any problems with the Android version review. Also, the iOS version delivered through TestFlight are working fine.
Review device details:
Device type: iPad Air 11-inch (M2)
OS version: iPadOS 18.1.1
Topic:
App Store Distribution & Marketing
SubTopic:
App Review
Tags: