render :new is not working anymore when I'm using services - ruby

Question

I'm trying to learn about services in Rails in order to avoid fat controllers.
Here a tried a simple product review creation
class ProductReviewsController < ApplicationController
before_action :set_product, only: :create
def new
#product_review = ProductReview.new
#product = Product.find(params[:product_id]) end
def create
if AddReviewService.call(product_review_params, #product)
redirect_to product_path(#product)
else
render :new
end
end
private
def set_product
#product = Product.find(params[:product_id]) end
def product_review_params
params.require(:product_review).permit(:content, :rating) end end
The thing is that in the case of wrong parameters for the review the render :new generates the following error :
screenshot of error received
Showing /home/miklw/code/michaelwautier/multitenant_app/app/views/product_reviews/new.html.erb where line #3 raised:
undefined method 'model_name' for nil:NilClass
Extracted source (around line #3):
1 <h1>New review for <%= #product.name %></h1>
2
3 <%= simple_form_for [#product, #product_review] do |f| %>
4 <%= f.input :content %>
5 <%= f.input :rating %>
6 <%= f.button :submit %>
Rails.root: /home/miklw/code/michaelwautier/multitenant_app
Application Trace | Framework Trace | Full Trace
app/views/product_reviews/new.html.erb:3:in `_app_views_product_reviews_new_html_erb__802305224391576972_70155240081100'
app/controllers/product_reviews_controller.rb:14:in `create'
Request
Parameters:
{"utf8"=>"✓",
"authenticity_token"=>"Z7YeYvXKKr7uYhANlevZ4H8U00p9givKzXzfue4pNFk0jE2DtTNY7Eacqati+V8IihSofLc2WPa4ZBzR2o0v5w==",
"product_review"=>{"content"=>"te", "rating"=>"9"},
"commit"=>"Create Product review",
"product_id"=>"4"}
Toggle session dump
Toggle env dump
Response
Headers:
None
In the error page console, if I type #product, I get the expected product object, but #product_review is nil.
BUT, if I use the regular way (see below), the form gets re-render as it should, with the notice message of the form
class ProductReviewsController < ApplicationController
before_action :set_product, only: :create
def new
#product_review = ProductReview.new
#product = Product.find(params[:product_id])
end
def create
#product_review = ProductReview.new(product_review_params)
#product_review.product = #product
if #product_review.save
redirect_to product_path(#product)
else
render :new
end
end
private
def set_product
#product = Product.find(params[:product_id])
end
def product_review_params
params.require(:product_review).permit(:content, :rating)
end
end
Any idea what could cause this issue ?
EDIT : Here is the service I call :
class AddReviewService < ApplicationService
attr_reader :content, :rating
def initialize(params, product)
#content = params[:content]
#rating = params[:rating]
#product = product
end
def call
review = ProductReview.new(content: #content, rating: #rating)
review.product = #product
return true if review.save
return false
end
end
EDIT 2 : returning the review when saved
def call
review = ProductReview.new(content: #content, rating: #rating)
review.product = #product
return review if review.save
return false
end