This is exactly what I did for one of my apps when I moved the codebase from Objective-C to Swift and SwiftUI. Zero issues. I'm not sure the OP has explained their issue very well.
As I said in my reply above, if the OP has uploaded a new binary and it's 'turned into a new app' then they have to have created a new app in App Store Connect otherwise Xcode will not upload the binary.
Topic:
App Store Distribution & Marketing
SubTopic:
General