I am trying to authenticate my domain on Mailerlite, however it is failing every single time.
What steps have you taken to resolve the issue?
I tried to authenticare Cloudflare domain via automatic methods as well as manually, checked all records, ensured there is only 1 v=spf1 record, however it is not authenticating. When I try to check records on Mailerlite, it shows no records found.
What feature, service or problem is this related to?
Yes That setting is flattening the CNAME for your DKIM record so if the provider it trying to validate that your records returns a CNAME, it can’t.
You can turn that off globally then if you want to enable flattening for specific DNS records you can do so by setting the switch for each individual DNS record.