Using “real” names for network devices instead of the IP addresses on home networks without using a host file can be iffy. I’ve seen it multiple times before myself where I can access via the IP address but not via the host name. Just access it via the IP address and be done with it. Don’t worry about it. You can create a “hosts” file which will tell your machine to use a specific name for a specific IP address.
Here’s a quick help article I found online:
Create a new Windows hosts file?
Google does a nice AI overview if you search on Good for “create host file windows 10”
As for the “ghost” NAS don’t worry about it. These are all the default shared folders of the QNAP. You have some default music samples and photos just to show you what the thing can do. That’s all. You can ignore all those and just use the device for your backups.