laravel save method not saving data completely - php

Question

I am using Laravel to create a web bot that collects data from other websites and stores it in my MySQL database. When I want to save body I use dd($this->render($post)); and it is good. Yet, when I use $post->save() for saving my post in db, it not saving the body of my post completely and some of text is missing.
My body is at least 10000 characters and I always have this problem.
I checked text and longtext for body column type and is not there any difference...
Where is problem?
edit :
this is my index method :
public function getIndex()
{
$temp = App\Temp::where('status' , 0)->orderBy('id' , 'desc')->first();
$temp->status = 1;
$temp->save();
$post = new App\Post;
$post->title = $temp->title;
$post->link = $temp->link;
$post->desc = $temp->desc;
$post->cat_id = $temp->cat_id;
$post->url_id = $temp->url_id;
$post->body = $this->render($post);
$post->save();
echo "+";
}
When I am using dd($this->render($post)); before save, it shows full text without any problem... but after save when I fetch the body, some characters is missing from the end of post...
and this is render() method...
public function render($post)
{
echo "Start : ";
$this->ftp->createFolder('/'.$post->url_id.'/'.$post->id."/");
echo "Dir - ";
$mixed_body = $this->desc($post->title);
echo "Mix - ";
$body ="";
$body = $body . '<h3><a href='.$this->postUrl.'>'.$this->postTitle.'</a></h3>';
echo "Title - ";
while(strlen($mixed_body) > 100)
{
$body = $body . $this->randImage($post);
$body = $body . $this->randTitle();
//insert a random paragraph
$number = rand(100 , strlen($mixed_body));//temporary
$paragraph = substr($mixed_body , 0 , $number);
$mixed_body = substr($mixed_body , $number , strlen($mixed_body)-$number);
$body = $body . '<p>' . $paragraph . '</p>';
echo "P|";
}
echo "\nDone : ".strlen($body);
return $body;
}
others methods in render() are appending some text to $body and those are not important.
and my model :
<?php namespace App;
use Illuminate\Database\Eloquent\Model;
class Post extends Model {
public function tags()
{
return $this->hasMany('App\Tag');
}
}

Answer 1

I find my problem reason...
sometimes I have a character like � in my body that laravel not saves the characters after it...
I find to use this line to delete � character...
$post->body = mb_convert_encoding($this->render($post), 'UTF-8', 'UTF-8');
thanks from all to help me, I have a very bad headache and want to rest...
thanks from all again, good night/morning/afternoon (according to your time-zones) :)