Pretty minor issue in that one device is showing as a device I do not have here.
I have a Smart-Plug currently with a fixed IP assigned by my router. In the router it is identified as SmartPlug-Washer but shows in my Pihole running on a 4b as Living-Room-TV, I've added now to the etc/hosts file as SmartPlug-Washer
In none of the files does Living-Room-TV appear here. It is a device on the network at my other place. Searching on the Pi4B the only reference that comes up if I do find ./ -type f -name "*.*" -exec grep 'Living-Room' {} \; is in the binary ftl.db.
Not a big issue, just a bit confused as to where it is pulling the name from. It misidentified with the same name when I first connected before allocating a fixed IP in the router when it was reporting to the the router as P110.
Probably the new device (SmartPlug-Washer) is using the same IP previously used by Living-Room-TV and you are using the same database for you new place.
Pi-hole doesn't know you are in a new place and it is getting the name for this IP from the database (pihole-FTL.db).
In the web interface, do you see these hostnames in Tools > Network page?
This was a new install to a spare Pi4B albeit it had been used several months ago, maybe as much as a year at my other place. The Piholes at the other place are still running as we're currently forced to keep the two places going. I did copy over the settings by importing with the teleporter and then changing the addresses. It is a different address range here to there too, I do regularly connect back via a self hosted VPN hence making sure to use the same ranges.
In Tools > Network it appears for 2 different address with the Living-Room-TV name
I suspect then I brought the name in when I used the teleporter but why it gets picked up when the address range is different as is the MAC I am unsure.
As well as the hosts which had no effect I've added it to the local DNS record, the custom.list and now shows up as expected.