Do you scan from WAN or LAN side? I tried a IP scan from a iPad on my router from the LAN side and that scanner shows the system settings hostname of the router for that IP adress.
The OpenWrt devices have only a WAN site that connect to my local network although one of them does not a TL-MR3020 mini router but it also does not shows his hostname.
Duno what "A" and "PTR" records are, I have to search and learn that first.
If success I will report the results thanks for the advice.
I have set the hostname in Network / Interfaces / Lan and there I fillin the hostname.
But it is in fact the WAN site who would to have an hostname assign to if I'm not mistaken.
Just don't know how to that as is not a normal thing to do.