SSL Certificate Error - Connection is not secure

I am new to Zoho Desk, but I've tried to link our new Zoho helpdesk to our domain via the subdomain https://helpdesk.leannova.de

It appears the CNAME change we implemented is working, but we're getting an SSL error that looks like this:

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Your connection isn't private

Attackers might be trying to steal your information from helpdesk.leannova.de (for example, passwords, messages, or credit cards).

NET::ERR_CERT_COMMON_NAME_INVALID

This server couldn't prove that it's helpdesk.leannova.de; its security certificate is from sales.swift360connect.co.uk. This may be caused by a misconfiguration or an attacker intercepting your connection.

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I can see from this portal that others have run into this problem, which apparently requires some assistance from the Zoho team to resolve.

How can I get the ball rolling?

Thanks,
Christopher