Laravel - foreach local variable is overwriting the global variable

Today i have faced a very strange issue. I have a controller from where i am sending three variables to the view sections thread and threads. In my view i am looping through all the sections with foreach loop like this:

@foreach($sections as $i => $section)

and for each section i am creating a div and giving that id like this:

id="-

now in this div i am looping through all the threads like this:

@foreach($threads as $thread)

and creating div for each thread. Now the problem is that when the loop for threads completes the last item in the threads which is store in local variable thread, overwrites the thread variable sent from the view. Now, i know that to resolve this i can rename the local variable in foreach loop to something else but my question is why is this happening? why is this local variable overwriting my global variable ?

Here is my controller:

    public function show($slug)
    {
        return view('thread.show')
            ->with('sections', Section::all())
            ->with('threads', Thread::all())
            ->with('thread', Thread::where('slug', $slug)->first());
    }

View:

@foreach($sections as $i => $section)
 <div class="tab-pane fade" id="-">
  @foreach($threads as $thread)
   <div class="card mb-3">
    
   </div
  @endforeach
 </div>
@endforeach

Now here is the screenshot of the rendered html:

The thread name is page-172 the id for the first div is rendered fine but look at he id of other two divs section-341 which is the last item in the threads

via Chebli Mohamed