fungus/Assets/Fungus/UI/Scripts/SelectOnEnable.cs

using UnityEngine;
using UnityEngine.UI;

namespace Fungus
{
    [RequireComponent(typeof(Selectable))]
    public class SelectOnEnable : MonoBehaviour
    {
        private Selectable selectable;

        private void Awake()
        {
            selectable = GetComponent<Selectable>();
        }

        private void OnEnable()
        {
            selectable.Select();
        }
    }
}