I can confirm that cloudflare mode is working as expected. There are a number of steps and many points of failure to this process. If you would like help, please provide much more detail about what you have tried that didn't work, error msgs, etc.

Some questions that may help to determine where you are going wrong:

-Are you able to crawl your network and find "good" nodes, or no? (ie: what does the contents of the dnsseed.dump file look like?)
-Did you already get confirmation from cloudflare that your domain has been activated with cloudflares nameservers?
-Can you post a portion of the output from the "python3 seeder.py" cmd?