You've lost me, why would they use Cloudflare but not want it cached by Cloudflare? @Day_ do you have any idea whats going on as I'm lost, I can't even see a setting for that.
This site also have the same Dynamic setting https://www.hmfckickback.co.uk/ whilst using Cloudflare.
So for some reason, mine is set to Bypass, whilst other sites show as Dynamic, but from what you're saying neither are doing anything.