Question Crouch - Animator Doesn't Play Full Animation

Hi,
I'm trying to implement a Crouch control for a platformer. My bool variables appear to be working correctly, but the animation only plays the first frame. I'm obviously not using Exit Time on the Animator as I want the animation to play immediately as it's a 2D game. I've tried various methods in my script, but the frames just don't play through.

The other scripts I have don't effect the Crouch script, as the problem persists even when they are disabled (I'm keeping my scripts seperate for future reference and modularity).

I want the player to stay crouched whilst the button is pressed, then when released the crouching is cancelled and it goes back to the Idle animation.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PlayerCrouch : MonoBehaviour
6. {
7.  
8.  
9.     public Animator animator;
10.  
11.  
12.     // Update is called once per frame
13.     void Update()
14.     {
15.         // Crouch True
16.         if (Input.GetButtonDown("Crouch"))
17.         {
18.             Debug.Log("True");
19.             animator.SetBool("isCrouching", true);
20.  
21.         }
22.  
23.         // Crouch False
24.         if (Input.GetButtonUp("Crouch"))
25.         {
26.             Debug.Log("False");
27.             animator.SetBool("isCrouching", false);
28.  
29.         }
30.  
31.  
32.     }
33.  
34.  
35. }