I found a post that submitted the same issue, but the solution was not made public. I didn't get a reply to my comment at the bottom of the post, so I'm pasting the content of the post here.
I am a developer working on iOS apps.
I would like to report an issue occurring in iOS 18 beta and iOS 18.1 beta.
Our company has two Enterprise accounts, and we are developing two apps:
A app / TeamId: ABCDEFG
B app / TeamId: HIJKLMN
When we distribute these apps, which have different TeamIds, and install them on a device running iOS 18 beta, both apps install successfully, but only one app will run.
(Other app crashed immediately after being launched.)
This issue does not occur on versions prior to iOS 18. I would like to know if this is a problem that will be resolved in future updates, or if it is a policy change.