Let’s take a step back. We don’t recommend, or provide tech support for, folks using cloudflare in front of our CDN. Check out this article with some of the downsides:
but TL;DR we do not provide tech support for that configuration and we do not expect it to work perfectly.
We’ll be happy to support your use case as it occurs without cloudflare in front so let me know if you have reproduction steps for that and I’ll be happy to take another look. As far as I can tell, cloudflare returns a 200 there which you’re welcome to discuss with their support team, but netlify provides a 301 redirect to https://cms-gtm3.fundbox.com/landing-pages/qbd-2019-01/ as you’ve configured.