I compiled this using Xcode 16RC 16A242 (instead of 15) and it now just about works.
In iPadOS 18RC it works perfectly.
In iOS 17.6.1 the swipe does not react when started from on top of the button but the showTab2 property does not change either so it remains consistent.
It seems this is a problem in Xcode 15 but it has been fixed in Xcode 16 as Sydney 🙏 suggested.
PS: 🏆Kudus to Xcode Cloud for making this test so easy to perform. I'd never used it before and it was truly simple to onboard.
Topic:
UI Frameworks
SubTopic:
SwiftUI
Tags: