The phone as hotspot doesn't use its own DNS
This answer could be written thanks to Irfan Latif's comments.

Is this a bug or a &quot;feature&quot;? It's expected behavior (see details in the first comment).

Can it be corrected without rooting the phone? Yes. I installed Virtual Hosts, created a one-line file containing 192.168.43.44 laptop and pointed the app to it. The app is really easy to turn on/off, so I can use it only when needed.