Root domain not redirecting to www domain

I have 3 exact cases where the root domain doesn’t redirect to the main domain. Meaning xyz.com doesn’t redirect to www.xyz.com. So, only www.xyz.com works out

I’m not sure what to do since the connection to my domain provider is accurate

Working here on my part of the net. I suspect you have cached DNS entries on your device, local network, or ISP.

That’s strange. Is there a way I could correct this? Something I could do to make it work?

Not strange at all, its how browsers work.
You could clear your browser cache, try another browser or device, you’ll see it redirects fine.