Find out computer name or at least a hint with a known IP address?

I have an IP address in my home network that is supposedly active but I can't assign it. I have now given names to all PCs and laptops so that I can clearly see them. I don't have anything for this address. It is also located in the address area in my home network. I also have the MAC address. Is there a trick I can use to find out which device it is?
Possibly. A tablet or cell phone?

I have already used the CMD command nbtstat -a. It says "host not found".
An IP scanner only brings the information I already have.
The ping times are relatively high (around 200ms). Is connected via Wi-Fi

Switch off all devices / disconnect them from the network. Then restart the router. Look in the DHCP overview which devices are in there now. Should be empty. Then turn on device by device and see which IP you add.

Just lock it out. Then you know what is no longer possible.

Throw out, MAC filter in and you're done. If it's something you're missing, you'll notice it, if not better.

Otherwise it could well be a smart home device, a smart socket, lamp, loudspeaker and even fire alarm. You often forget what kind of stuff you have that shines.

Throw out the device, as KolnFC wrote

Ha! Have found it. First looked in all portable devices lying around in the settings. Was my wife's cell phone. Strange that there's no name anywhere. For me and my daughter's Iphone, this is in plain text. I must give the thing a name.