Dispose doesnt work when page is refreshed (server-side blazor)

Hello I was trying to make the fetchdata example update values without refreshing page or clicking buttons. And I found out that I can use timer which seemed like working ok. But after testing with different data it was acting strange and I found out that page doesnt dispose the timer when I go to different page and its not displayed anymore. That was solved by adding dispose but it didnt solve different issue… When I press F5 while on /fetchdata page it reloads and doesnt dispose the timer. And then it runs twice. I tried it by adding int into ForecastService and it increment everytime GetForecastAsync is called. After 10 refreshes it increment +10 every second instead of +1. I hope it makes sense.

@functions {
WeatherForecast[] forecasts;
Timer timer;
private async void Update()
{
    forecasts = await ForecastService.GetForecastAsync(DateTime.Now);
    StateHasChanged();
}

protected override async Task OnInitAsync()
{
    timer = new Timer(1000);
    timer.Elapsed += (sender, args) => Update();
    timer.Start();
    Update();
}

public void Dispose()
{
    timer.Dispose();
}
}