Sometimes, restarting the Mac and the device takes care of stuff like this. It's worth a try.

Try Xcode 15.2. I'm sure they've fixed a lot of bugs

Do you have an example of the link? What do you see in Chrome when it doesn't work? I'm sure Chrome has debug tools to figure out what the response is. If you post some more info or screenshots, someone can help.

Hello This is a developer forum. You should post your question in the support forum: https://discussions.apple.com/welcome

This is a developer forum. You should post your question in the support forum: https://discussions.apple.com/welcome

Xcode 15.2 works for my iOS 17.2 device as well. Try restarting your device. Sometimes that fixes weird issues. Also, I checked /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport and even I see only up to 16.4. I don't think that's related to the problem.

Since there's no clear explanation, I would make 2 changes to see if they fix the issue: static DWNotificationView *singleton = nil; //nil and NULL are supposed to be the same but nil is preferred for objects in Obj C if (singleton == nil) //this also shouldn't matter but you never know if fast optimization is picky

Are you able to test it on an actual device?

I think it's related to the following note on https://developer.apple.com/documentation/bundleresources/information_property_list/uirequireddevicecapabilities/: Important Your app must include the UIRequiredDeviceCapabilities key in the Information Property List file that you submit with your binary. For app updates, you can only maintain or relax capability requirements. Submitting an update with added requirements would prevent some customers who previously downloaded your app from running the update. If you've changed UIRequiredDeviceCapabilities from your previous submission, revert the changes and I think it'll work.

I think of TestFlight as a staging App Store. You'll publish your app to TestFlight so that your selected TestFlight users can try it. Fix bugs and publish updates to TestFlight. Once you're happy with the testing/feedback, you'll release that version to the App Store.

It's difficult to say. What are you using it for? If it doesn't fall into one of the listed modes, I would use default and expect the OS to do the right thing.