hasOneThrough returns the first row not the related row

I have these tables:

grades:

id | grade
 1  |   1
 2  |   2

services:

id | service
1  | service1
2  | service2

comments:

id | comment
1   | comment1
2   | comment2
3   | comment3  

comments_services:

id | service_id | grade_id(nullable) | comment_id
1  |      1     |         null       |      1
2  |      1     |           2        |      2
3  |     2      |            3       |      3 

In comments model:

public function services(){
     return $this->belongsToMany(Service::class, 'comments_services', 'comment_id', 'service_id', 'id')- 
   		>with('grade');
}

In services model:

public function grade(){
    return $this->hasOneThrough(Grade::class, Service::class, 'service_id', 'id', 'id', 'grade_id');
}		

The issue is with the grade function it should return the related grade but it returns the first row instead.

This is the query generated:

select `grade_id``, `grade`, `comments_services`.`service_id` as `laravel_through_key` from `grades` inner join `comments_services` on `comments_services`.`grade_id` = `grades`.`id` where `comments_services`.`service_id` in (1, 2, 6, 10)

So if there are multiple comments with service_id in (1,2,6,10) it would return the first one.

I think the solution would be to include the comment_id in the query or condition with comments_services.id.

Also, I tried to split this relation instead of using hasOneThrough:

//comments model
public function services(){
    return $this->belongsToMany(Service::class, 'comments_services', 'comment_id', 'service_id', 'id')->with('ser');
}	

//services model
public function ser(){
	 return $this->hasOne(Service::class, 'service_id', 'id')->with('grade')
}

//comments_services model
public function grade(){
	 return $this->belongsTo(Grade::class, 'grade_id', 'id')
}

This is not working either.

CommentController:

public function edit(Request $request, Comment $comment){
    return view('comments.edit', compact('comment'));
}

In the case of hasOneThrough this would be returned for all comments with grades:

"grade" => array:3 [▼
    "id" => 1
    "grade" => "1"
    "laravel_through_key" => 2
  ]