Thanks for sharing your query with us here in the Shopify Community.
I’d like to share some info on what we can and cannot advise on from here in Shopify.
We would always advise merchants to ensure they have one A record which is set to the Shopify IP address 23.227.38.65, and one CNAME record for the value ‘www’ that is set to ‘shops.myshopify.com’.
Outside of this we would recommend the removal of any other A or CNAME records as they can interfere with the connection of your domain to Shopify and can affect the provision of your domain’s security cert.
If you’re unsure how this will work in the context of your third-party domain you would need to consult your domain provider’s support team who will be able to confirm how their service works in this regard.