Laravel model Trailing Data when save the model

I have some code like this

    $editStuState = StuAtt::where('studentId' , '=' , $id)->first();
    $editStuState -> leave +=1;
    $editStuState -> present = $editStuState -> present-1;
    $editStuState->update();
                            //OR
    $editStuState->save();
    return 'this is good';

I can't save or Update my data, when I remove Update and Save related line it can print text.

this is the dd($editStuState) data

StuAtt {#382 ▼
  #table: "stu_attendance"
  #connection: "mysql"
  #primaryKey: "id"
  #keyType: "int"
  +incrementing: true
  #with: []
  #withCount: []
  #perPage: 15
  +exists: true
  +wasRecentlyCreated: false
  #attributes: array:7 [▼
    "id" => "7"
    "studentId" => "1"
    "present" => "2"
    "absent" => "1"
    "leave" => "10"
    "created_at" => "2018-04-16 11:17:41.176898"
    "updated_at" => "2018-04-16 06:47:41.000000"
  ]
  #original: array:7 [▼
    "id" => "7"
    "studentId" => "1"
    "present" => "2"
    "absent" => "1"
    "leave" => "10"
    "created_at" => "2018-04-16 11:17:41.176898"
    "updated_at" => "2018-04-16 06:47:41.000000"
  ]
  #changes: []
  #casts: []
  #dates: []
  #dateFormat: null
  #appends: []
  #dispatchesEvents: []
  #observables: []
  #relations: []
  #touches: []
  +timestamps: true
  #hidden: []
  #visible: []
  #fillable: []
  #guarded: array:1 [▶]
}

I also got this error form laravel 5.6 it

InvalidArgumentException
Trailing data

I check my code line by line and I think is not relevant to Carbon according to my research. How I should fix this?

via Chebli Mohamed