Hello!
The same thing happens if the fqdn points to a local device, which is the normal use case for me.
The feeling I get from aliases is that they are finicky.
The idea that you could setup an alias and get one result, and that I could setup a similar alias (I used a /28 network, not a single host in my test) and get a different result bears this out.
I get the same vibe when reading through bugs like https://redmine.pfsense.org/issues/9296
There is lots of interesting reading in redmine about aliases.
I hope that aliases are working well for most people, but I do have to agree that at times they have "driven me crazy".
John