Hi, @Marc73 thanks for your post and welcome to the community can you please share your web URL so I can let you know the exact reason for the slow speed. Thanks and Best Regards
I don't have experience with GoDaddy but the domain transfer to Shopify is totally simple and I think it's rather simple.
I found this tutorial https://help.shopify.com/en/manual/online-store/os/domains/add-a-domain/using-existing-domains you can check it out.
No sure if Go Daddy make your store speed slower, but if you transfer the domain to Shopify, you will find it easier to manager the admin tasks for the domain, saving your time, I mean.
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Thank you and wish you the best of luck!
I doubt it. A domain is just a pointer to your server. Technically, there could be a delay if something is wrong with GoDaddy, but unlikely in my opinion.
I use GoDaddy for most of my domains (including Shopify stores).
From my experience, I don't think that a domain name can have an impact on your Shopify store because Godday will redirect your visitor to your Shopify store