Unexpected (automatic) navigation with SwiftUI on watchOS

I have a simple watchOS 6.2.8 SwiftUI application in which I present a list of messages to the user.

These messages are modelled as classes and have a title, body and category name. I also have a Category object which is a view on these messages that only shows a specific category name.

Code Block 
class Message: Identifiable {
		let identifier: String
		let date: Date
		let title: String
		let body: String
		let category: String
		
		var id: String {
				identifier
		}
		init(identifier: String, date: Date, title: String, body: String, category: String) {
				self.identifier = identifier
				self.date = date
				self.title = title
				self.body = body
				self.category = category
		}
}
class Category: ObservableObject, Identifiable {
		let name: String
		@Published var messages: [Message] = []
		
		var id: String {
				name
		}
		init(name: String, messages: [Message] = []) {
				self.name = name
				self.messages = messages
		}
}

Category itself is an @ObservableObject and publishes messages, so that when a category gets updated (like in the background), the view that is displaying the category message list will also update. (This works great)

To store these messages I have a simple MessageStore, which is an @ObservableObject that looks like this:

Code Block 
class MessageStore: ObservableObject {
		@Published var messages: [Message] = []
		@Published var categories: [Category] = []
		static let sharedInstance = MessageStore()
		func insert(message: Message) throws { ... mutage messages and categories ... }
		func delete(message: Message) throws { ... mutage messages and categories ... }
}

(For simplicity I use a singleton, because there are problems with environment objects not being passed properly on watchOS)

The story keeps messages and categories in sync. When a new Message is added that has a category name set, it will also create or update a Category object in the categories list.

In my main view I present two things:

• An All Messages NavigationLink that goes to a view to display all messages

• For each Category I display a NavigationLink that goes to a view to display messages just in that specific category.

This all works, amazingly. But there is one really odd thing happening that I do not understand. (First SwiftUI project)

When I go into the All Messages list and delete all messages containing to a specific category, something unexpected happen when I navigate back to the main view.

First I observe that the category is properly removed from the list.

But then, the main view automatically quickly navigates to the All Messages list and then back.

The last part is driving me .. crazy .. I don't understand why this is happening. From a data perspective everyting looks good - the messages have been deleted and the category too. The final UI state, after the automagical navigation, also looks good - the message count for All Messages is correct and the category with now zero messages is not shown in the list anymore.

Full project at https://github.com/st3fan/LearningSwiftUI/tree/master/MasterDetail