It sounds like your previous provider was using Cloudflare for your domain.
Unfortunately the community is unable to assist you with issues such as this where an old provider used Cloudflare for SaaS. Please contact your old provider and ask them to remove any Cloudflare configurations for your domain, specifically SSL for SaaS / Custom Hostnames. If you previously used HubSpot, please ignore this and move to the paragraph below.
If you are unsure who the previous provider is or they say they are unable to help you, please email
[email protected] with the subject
Cannot remove custom host name and details of the issue. Once you’ve done that you’ll receive an automatic response with a ticket number. Please post that here so we can escalate it. Once you have reached out to Support they will ask you to verify domain ownership of the domain by adding a
txt record to the domain in order to verify domain ownership.