How to delete data using Eloquent query?

I can not delete a row using a simple eloquent query. Even when I am using eloquent can not get the data from DB. I am getting null. But, in DB query method at least I am getting data but can not delete then. Following is my code:

DB::transaction(function () use ($lead, $comment, $request) {
    $lead->save();
    $lead->comments()->save($comment);

    if ($request->deleteAppointment) {
        $calendarEvent = DB::table('calendar_events')->where('id', $request->appointmentId)->first(); // I am getting data here.
        $calendarEvent = CalendarEvent::find($request->appointmentId); // But, here I am getting null, don't know why!
        
        if ($calendarEvent != null) {
            $calendarEvent->delete();
        }
    } 

My goal is to get the data using Eloquent and then Delete from database.

update: My Database Table

CalendarEvent.php model

class CalendarEvent extends Model
{
    use SoftDeletes;

    /**
     * @var array
     */
    protected $casts = [
        'event_begin' => 'datetime',
        'event_end'   => 'datetime',
        'options'     => 'array',
    ];

    /**
     * @var array
     */
    protected $guarded = [
        'id',
    ];

    /**
     * @return mixed
     */
    public function users()
    {
        return $this->morphedByMany(User::class, 'eventable');
    }

    /**
     * @return mixed
     */
    public function attendees()
    {
        return $this->morphedByMany(User::class, 'eventable')->withPivotValue('role', 'atendee');
    }

    /**
     * @return mixed
     */
    public function companies()
    {
        return $this->morphedByMany(Company::class, 'eventable')->withPivotValue('role', 'company');
    }

    /**
     * @return mixed
     */
    public function invitees()
    {
        return $this->morphedByMany(User::class, 'eventable')->withPivotValue('role', 'invitee');
    }

    /**
     * @return mixed
     */
    public function leads()
    {
        return $this->morphedByMany(Lead::class, 'eventable')->withPivotValue('role', 'lead');
    }
}