Player sticks to ground occasionally after trying to jump

Hello all!

I've been trying to make it so that my Rigidbody player jump correctly while still keeping all of the correct checks in place. My issue is that occasionally the player will get stuck when hitting the "Jump" button. When I inspect the player when this happens, it will show that both the "onGround" and "firstJump" checks as true even though the player is already touching the "Jumpable" surface. The main character also has the ability to hover with a gameobject that follows him around (like Sonic & Tails or DKC) which I don't think should be the problem, but just in case I added it in the complete script I've made. I may just have some booleans not placed correctly, or I could be going the completely wrong direction in this. I'm just getting back into scripting and Unity so any help would be appreciated!!!

Thanks for your time guys. Please let me know if I need to explain or include anything else!

 //Character state variables
 var isLoki : boolean = true;
 var isHoodie : boolean = false;
 
 //Object Variables
 var inactiveChar : GameObject;
 
 //Material variables
 var matArray : Material[];
 
 //Movement variables
 var speed : float = 6.0;
 var maxSpeed : float = 10.0f;
 var jumpHeight : float = 8.0;
 var onGround : boolean;
 var firstJump : boolean;
 private var jumped : boolean;
 private var moveRight : boolean;
 private var moveLeft : boolean;
 private var hoverRight : boolean;
 private var hoverLeft : boolean;
 private var hoverTimerEnd : boolean;
 
 //Hovering variables
 public var isHovering: boolean;
 var hoverSpeed: float = 3.0;
 var maxHoverTime: float = 2.0;
 private var currentHoverTime: float;
 
 //Offset variables
 var inactivePlayerOffset : float = -1.5;
 private var relativePositionOffset : Vector3 = Vector3(0,0,0);
 
 function Start() {
 
     //Setting hover timer to 0
     currentHoverTime = 0;
 
     //Instantiates inactive character
     Instantiate (inactiveChar, transform.position + relativePositionOffset+(transform.right*inactivePlayerOffset), Quaternion.identity);
 }
 
 function FixedUpdate() {
 
     //Trying to limit speed
     if (GetComponent.<Rigidbody>().velocity.magnitude > maxSpeed){
         GetComponent.<Rigidbody>().velocity = Vector3.ClampMagnitude(GetComponent.<Rigidbody>().velocity, maxSpeed);
     }
 
     //Right/left movement (physics)
     if (moveRight == true) {
         GetComponent.<Rigidbody>().velocity.x = speed;
     }
 
     if (moveLeft == true) {
         GetComponent.<Rigidbody>().velocity.x = -speed;
     }
 
     //Hover movement (physics)
     if (hoverRight == true) {
         GetComponent.<Rigidbody>().velocity.x = hoverSpeed;
     }
 
     if (hoverLeft == true) {
         GetComponent.<Rigidbody>().velocity.x = -hoverSpeed;
     }
 
     //Jump (physics)
     if (jumped == true) {
         GetComponent.<Rigidbody>().velocity.y = jumpHeight;
     }
 
     //Hover constraints
     if (isHovering == true) {
         GetComponent.<Rigidbody>().useGravity = false;
         GetComponent.<Rigidbody>().constraints = RigidbodyConstraints.FreezePositionY | RigidbodyConstraints.FreezePositionZ | RigidbodyConstraints.FreezeRotation;
     }
 
     if (hoverTimerEnd == true) {
         GetComponent.<Rigidbody>().useGravity = true;
         GetComponent.<Rigidbody>().constraints = ~RigidbodyConstraints.FreezePositionY;
         GetComponent.<Rigidbody>().constraints = RigidbodyConstraints.FreezePositionZ | RigidbodyConstraints.FreezeRotation;
         hoverTimerEnd = false;
     }
 }
 
 function Update() {
 
     /*//Loki moveset
     if (isLoki == true && !isHoodie) {
 
     }
 
     //Hoddie moveset
     if (isLoki == true && !isHoodie) {
 
     }*/
 
     //Hover Timer
     if    (!onGround && isHovering == true){
         currentHoverTime += Time.deltaTime;
     } 
 
     else {
         currentHoverTime = 0;
     }
 
     //Normal Movement
     if (Input.GetButton ("Right") && !isHovering) {
         moveRight = true;
     }
 
     else {
         moveRight = false;
     }
 
     if (Input.GetButton ("Left") && !isHovering) {
         moveLeft = true;
     }
 
     else {
         moveLeft = false;
     }
 
     //Hover movement
     if (Input.GetButton ("Right") && !onGround && isHovering == true) {
         hoverRight = true;
     }
 
     else {
         hoverRight = false;
     }
 
     if (Input.GetButton ("Left") && !onGround && isHovering == true) {
         hoverLeft = true;
     }
 
     else {
         hoverLeft = false;
     }
 
     //BUG: Player uses jump right as they hit the ground, onGround and firstJump are true? if player not on ground && first jump == true (don't regular jump)
 
     //Jump
     if (Input.GetButtonDown ("Jump") && onGround == true) {
         jumped = true;
         firstJump = true;
     }
 
     else {
         jumped = false;
     }
 
     //Hover
     if (Input.GetButtonDown ("Jump") && onGround == false && firstJump == true) {
         firstJump = false;
         isHovering = true;
     }
 
     //Hover timer
     if (currentHoverTime > maxHoverTime) {
         isHovering = false;
         hoverTimerEnd = true;
     }
 
     // Character/material switch
     if (Input.GetButtonDown ("Switch")) {
 
         if (isHoodie == false && isLoki == true) {
             isHoodie = true;
             isLoki = false;
             GetComponent.<Renderer>().material = matArray[0];
         }
 
         else {
 
             if (isHoodie == true && isLoki == false) {
                 isHoodie = false;
                 isLoki = true;
                 GetComponent.<Renderer>().material = matArray[1];
             }
         }
     }
 }
 
 function OnCollisionEnter(collision : Collision){
 
     if (collision.collider.gameObject.layer == LayerMask.NameToLayer("Jumpable")) {
         firstJump = false;
         onGround = true;
         isHovering = false;
         currentHoverTime = 0;
         //Debug.Log("Jumpable!");
     }
 }
 
 function OnCollisionExit(collision : Collision) {
 
     if (collision.collider.gameObject.layer == LayerMask.NameToLayer("Jumpable")) {
         onGround = false;
         //Debug.Log("Not jumpable!");
     }
 }