Hello - I'm working on the challenge for Creating Validation Rules and when I check my challenge, I'm getting a message, "Challenge not yet complete... here's what's wrong: The validation rule failed to enforce the business logic". I can actually see that my validation rule message is being applied when I'm in an account and trying to create a related contact with a Mailing Postal Code different from the account's Shipping Postal Code. I can also successfully create a contact with no associated parent. I've attached a screenshot of the message generated as a result of my validation rule being applied. Does Trailhead ever report a failed challenge, even though it was developed correctly? Thanks in advance.

Matt