My last two cases both were a result of poor documentation. Most recently according to https://docs.blackbaud.com/email-resource-center/overview/client/sender-authentication/spf if you need to put parentheses around a DNS TXT record then say it in the original instructions in the notification email and in the more detailed instructions.

Then about a month ago I was on a call with BB support to try and have terms for dorms. Documentation that the technician had said this was possible but it was not in the sandboxed or production environments.