bollywood33 You might still get redirected if you loaded the page on your browser before making the changes, browsers cache redirects for https reasons and will still do it even when the server has been changed, that and rewrites on pages in the headers can be cached on the normal Cloudflare and browser cache. Using a online tool that does not use cache like https://wheregoes.com works really well for this.
I have never had a problem with the ACME rule before...
You can also just generate once
The other option is turn CF proxy off, generate cert and turn on again to flexible. The certificate will be there and work on our end so traffic is encrypted, but it won't renew, but that does not matter as even when it's expired the data transfer is STILL encrypted but just acts as a self signed cert and CF will give the user the updated CF proxy level certificate.