iOS App built with UCB development build flag crashes on launch (before Splash Screen displays)

Recently I upgraded an iOS app under development from 2017 to 2018.2.6. I rebuilt the app using UCB with the Development Build set. When I installed the app on an iPad, the app crashed before the Made in Unity splash screen appeared. If the app is built without the development build flag set and the app runs without issue.

So I did a little more digging into the issue. I had to back away from the app and went back to a bare bones Unity 2018.2.6 installation. I created a new project and didn't install any extra packages, I just used the default package installation. I never changed any settings. I added a single TextMeshPro text box and added a little bit of text. I saved everything and pushed all the files to a Bitbucket repository: the source files, the package manifest file, and the project settings. I then built the project with the latest compatible Unity 2018.x option, Xcode 9.4, and the development build flag not set. the app ran fine. I then tried it with the development build flag set and it worked fine.

So I did more digging. Eventually I discovered that having the development build flag set in UCB and setting the Players Scripting Runtime Version to .Net 4.x, Equivalent, scripting backend (which gets set automatically) to IL2CPP, and API compatibility to .Net 4.x caused the application to crash before the splash screen appeared. Has anyone heard about or seen this being a problem before? Any idea why this might be happening?

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My test environment
- Unity: 2018.2.6 on windows
- UCB: Latest 2018.2.x (was using 2018.2.8), Xcode 9.4, and Development Build flag set
- bitbucket repository with all source files, package folder, and project settings folder uploaded to the repository
- Player settings (in Unity Editor) changes: Scripting runtime version set to .Net 4. This modifies the scripting backend and API compatibility automatically and they weren't modified from the new settings.

The only changes to the Unity sample scene that gets created when a new project is created was to add a text box with a couple of lines of text.