Why do I have an infinite loop when using a middleware with Scrapy?

I am implementing a program to scrape job offers on a site. However, I have a problem: on this same site links are sometimes programmed with relative href, sometimes absolute (ex: sometimes I have https://fr.indeed.com => correct, but other times: /cmd/jobs => incorrect). It is therefore necessary to check before sending each request whether the request is correct. To do this, I coded a function in middleware that allows me to check it

class IndeedDomainVerificationMiddleware:
 
    def __init__(self, indeed_domain_url):
        self.indeed_domain_url = indeed_domain_url
 
    @classmethod
    def from_crawler(cls, crawler):
        return cls(indeed_domain_url=crawler.settings.get('INDEED_DOMAIN_URL'))
 
    def process_request(self, request, spider):
        if spider.name == 'Indeed':
            print(request.url)
            if self.indeed_domain_url not in request.url:
                new_url = self.indeed_domain_url + request.url
                print("New URL: %s" % new_url)
                return request.replace(url=new_url)
            else:
                pass
        return None

In middlewares.py

Then, in my settings I activate the middleware :

SCRAPEOPS_API_KEY = 'API KEY'
SCRAPEOPS_PROXY_ENABLED = True
SCRAPEOPS_PROXY_SETTINGS = {'country': 'fr'}
INDEED_DOMAIN_URL = "https://fr.indeed.com"
DOWNLOADER_MIDDLEWARES = {
   "Cy_Scraper.middlewares.IndeedDomainVerificationMiddleware": 543,
   "Cy_Scraper.middlewares.ScrapeOpsProxyMiddleware": 725,
}

I use a second middleware that allows me to use a proxy to avoid being detected.

However when I launch my spider I have an infinite loop.

I tried various things as implementing the middleware as a Spider middleware like shown there, but it didnt work, I kept having an infinite loop when returning the request, and having duplicate request when I return none

Saw the post from Rahul but it didn't help too.