Getting the exact same error. I rewrote my app with React Native and I'm trying to basically update the old one, have the same bundle ID in all my config files but when I try to archive it it is being treated as a new app in the dropdown at the top left of the window (strangely it is showing the name of the "new" app without a space). If you do find a solution pls let me know. I'm getting close to remove my old app from the App Store entirely and just submitting this as a new one, but of course that means I'll lose all existing reviews.

Were you able to find a solution to this? I'm having the same problem: I rewrote my Angular to React Native and I'm using the same bundle ID. However, when I archive and distribute the project it's throwing an error saying the bundle ID is already being used by another app in AppStoreConnect, which is in fact the app I'm trying to update. Are there any specific changes I need to make in the app config for AppStoreConnect to treat this as an update instead of a new submission? As I said the app bundle matches the one that's already online.