When connecting a domain to Shopify, the root domain will need to point to 184.108.40.206 for the "A" record and shops.myshopify.com for the CNAME of any subdomain. These are the only DNS settings we can accept in order to successfully connect your domain to your Shopify store. Any other "A" or "Cname" records added will likely lead to your domain either not connecting to your Shopify store, or throwing an error when trying to visit your store.
May I know why you're wanting to have a different IP for your subdomain? What are you trying to setup?