asynclocal culture

Program.cs

// See https://aka.ms/new-console-template for more information

using System.Globalization;
using System.Runtime.CompilerServices;

ShowCulture("start");
await SetFrenchAsync();
ShowCulture("end");

async Task SetFrenchAsync()
{
    ShowCulture("    start", "fench");
    CultureInfo.CurrentCulture = new CultureInfo("fr-fr");
    ShowCulture("    changed", "fench");
    await Task.Delay(100);
    await SetGermanAsync();
    ShowCulture("    end", "fench");
}

async Task SetGermanAsync()
{
    ShowCulture("        start", "german");
    CultureInfo.CurrentCulture = new CultureInfo("de-de");
    ShowCulture("        changed","german");
    await Task.Delay(100);
    await SetRussianAsync();
    ShowCulture("        end","german");
}

async Task SetRussianAsync()
{
    ShowCulture("            start", "russian");
    CultureInfo.CurrentCulture = new CultureInfo("ru-ru");
    ShowCulture("            changed","russian");
    await Task.Delay(100);
    ShowCulture("            end","russian");
}

void ShowCulture(string text, [CallerMemberName] string methodName = "")
{
    Console.WriteLine(text + methodName + " : " + CultureInfo.CurrentCulture);
}

// start<Main>$ : en-DE
//     startfench : en-DE
//     changedfench : fr-FR
//         startgerman : fr-FR
//         changedgerman : de-DE
//             startrussian : de-DE
//             changedrussian : ru-RU
//             endrussian : ru-RU
//         endgerman : de-DE
//     endfench : fr-FR
// end<Main>$ : en-DE