Resetting ui.Select in Google Earth Engine

ui.Select does not change its value when a placeholder text is changed. Therefore, within Reset button while resetting the items (according to me unnecessary) and changing the placeholder text to "Choose a location2..." of the select button, you are not changing the value of select, but merely changing the text that is displayed on the select button. This is why a change is not registered when you click on the same location again. You can verify this by printing select.getValue() after you click on Reset.

I think you want to set the location value to default (0,0) when you click on reset. Then, if you again click on the original location, a change will be registered. To achieve that, you can change your reset function as follows:

var Reset=ui.Button({
  label: "Reset Dropdown",
  onClick: function () {
    select.setValue("Choose a location...")
    // select.items().reset();
    // select.items().reset(Object.keys(places));
    // select.setPlaceholder('Choose a location2...');
    }
    
});

And explicitly set the default location within the select button.

Link to complete code.