ScrollView+Workaround.swift

import Foundation
import SwiftUI

extension ScrollView {

    /// Workaround for large titles flickering on collapse. Not applied for iOS 15+.
    /// Based on https://stackoverflow.com/a/67270977/99714 but avoids a questionable API by using a concrete type.
    func largeTitleFlickerWorkaround() -> some View {
        Group {
            if #available(iOS 15.0, *) {
                self
            } else {
                GeometryReader { geo in
                    WorkaroundScrollView(axes: axes, showsIndicators: showsIndicators, content: content.padding(geo.safeAreaInsets))
                        .edgesIgnoringSafeArea(.all)
                }
            }
        }
    }

    private struct WorkaroundScrollView<ScrollViewContent: View>: View {
        let axes: Axis.Set
        let showsIndicators: Bool
        let content: ScrollViewContent

        var body: ScrollView<ScrollViewContent> {
            ScrollView<ScrollViewContent>(axes, showsIndicators: showsIndicators, content: { content })
        }
    }

}

Usage.swift

import SwiftUI

struct ContentView: View {
    
    var body: some View {
        NavigationView {
            ScrollView {
                LazyVGrid(columns: [GridItem(.flexible(), spacing: 16), GridItem(.flexible(), spacing: 16)], alignment: .center, spacing: 32, pinnedViews: []) {
                    ForEach(0..<10) { _ in
                        Text("Hello, world!")
                    }
                }
            }
            .largeTitleFlickerWorkaround()
            .navigationTitle("Scroll me")
        }
    }

}