Python Behave - JSONDecodeError

I have a feature file with the following scenarios

      Scenario: POST Request
    And the title is "Bohemian Rhapsody"
    And the year is "2019"
    And the plot is "null"
    And the duration is "120"
    And the genres are " "
    Given the user makes a "POST" call to the "/resources/" endpoint
    Then you should receive status code "201"
    And title "Bohemian Rhapsody" should be in response body
    And year "2019" should be in response body

  Scenario: PUT Request /resources/{id}, where "id" represents the resource resource previously created
    And the title is "We will rock you"
    And the year is "2024"
    And the plot is "null"
    And the duration is "120"
    And the audio qualities are " "
    And the video qualities are " "
    And the genres are " "
    Given the user makes a "PUT" call to the "/resources/" endpoint
    Then you should receive status code "204"
    And title "We will rock you" should be in response body
    And year "2024" should be in response body

The second scenario relies on the "id" of the first response in order to update the resource previously created. The steps are below:

    @given('the user makes a "{method}" call to the "{endpoint}" endpoint')
def execute_request_to_endpoint(context, method, endpoint):
    global json_response
    if method == 'GET':
        response = requests.get(endpoint)
    elif method == 'POST':
        response = requests.post(endpoint, json=context.request_body)
    elif method == 'PUT':
        print(json_response)
        new_json_response = json.loads(json_response)
        movie_id = new_json_response['id']
        print(endpoint + str(movie_id))
        context.request_body = str(context.request_body).replace("\'", "\"")
        response = requests.put(endpoint + str(movie_id), json=context.request_body)
    context.response_body = response.json()
    json_response = json.dumps(context.response_body)
    context.status_code = response.status_code


@then('you should receive status code "{status_code}"')
def check_status_code(context, status_code):
    assert context.status_code == int(status_code)


@step('the title is "{title}"')
def set_title(context, title):
    context.request_body = {"title": title}


@step('the year is "{year}"')
def set_year(context, year):
    context.request_body['year'] = int(year)


@step('the plot is "{plot}"')
def set_plot(context, plot):
    context.request_body['plot'] = plot


@step('the duration is "{duration}"')
def set_duration(context, duration):
    context.request_body['duration'] = int(duration)


@step('the genres are "{genres}"')
def set_genres(context, genres):
    context.request_body['genres'] = genres


@step('title "{title}" should be in response body')
def check_title(context, title):
    assert context.response_body['title'] == title


@step('year "{year}" should be in response body')
def check_year(context, year):
    assert context.response_body['year'] == int(year)

I get an error like this simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0) even though I already did many attempts but never managed to complete successfully the second request in the second scenario. For debugging purposes I can see that I am able to print the response body from the first call {"id": 5000, "title": "Bohemian Rhapsody", "year": 2019, "plot": "null", "duration": 120} and I am also able to grab the endpoint /resources/5000 when printing it. So I am doing the PUT request but then I get the above error. I do not understand why the issue is only with the second request and not with the first since they are similar.