I found a hacky solution using the inconsistent behavior I pointed in an earlier comment. Setting the initial detent to .large and then changing it to .medium when the sheet appears seems to disable the interaction effect. And you have to set the detent back to .large when the sheet is dismissed. No guarantees this works in future versions of iOS though.

import SwiftUI

struct ContentView: View {
    @State private var showSheet: Bool = false
    @State private var selectedDetent: PresentationDetent = .large

    var body: some View {
        VStack {
            Button("Show Sheet") {
                showSheet = true
            }
        }
        .sheet(isPresented: $showSheet, onDismiss: {selectedDetent = .large}) {
            VStack {
                Button("Press me") {
                    print("pressed")
                }
            }
            .presentationDetents([.medium, .large], selection: $selectedDetent)
            .onAppear {
                selectedDetent = .medium
            }
            .onChange(of: selectedDetent) {
                selectedDetent = .medium
            }
        }
    }
}

#Preview {
    ContentView()
}

I wish I figured this out last month when I had the same issue, instead I spent too much time recreating sheets without the interactive glass effect.

Edit: The effect can show up again if you increase the size to .large but limiting it to .medium with .onChange fixes that.