First, check the log message created when launch app in XCode.
Log : "Message from debugger: Terminated due to signal 14"
If app suddenly closed after tens of seconds from launch, You can see the message above.
AppSealing is providing two kinds of Libs for Debug and Release, Release Lib should be used for uploading IPA at AppStore or TestFlight.
So if you do Release Running in XCode, you can meet this error.
How to solve :
AppSealing is providing Lib for Debug, You should use Debug Running in XCode rather than Release Running.