Why does the keyboard fall off after each character entered in the SwiftUI TextField and how best to fix it?

Question

iOS

I have an ObservableObject in parent View and child View:

import Parchment

class MainViewModel: ObservableObject {
    @Published var inputText = String()

    init() {}
}

struct ChildView: View {
    @EnvironmentObject var viewModel: MainViewModel

    var body: some View {
          PageView(/**/) {
          TextField("", $viewModel.inputText)
}
}
    }
}

Tried placing inputText in ObservedObject of child View, nothing changed.
As soon as I enter one character, the keyboard disappears. Apparently, SwiftUI starts redrawing the entire page, as a result of which the TextField ceases to be active.
How can this be fixed? Maybe somehow force the activation of the TextField, or call the keyboard?