Different macs have same name in airdrop

I have 2 macs. In "Sharing" one is Tom's MacBookPro and the other is Tom'sNewMacBookPro. Today in AirDrop a Finder window on "NewMacBookPro" correctly showed "MacBookPro", but a Finder window on "MacBookPro" also showed "MacBookPro" - itself! Confusing but I tried it anyway and dragging a file on "MacBookPro" to "MacBookPro" in the AirDrop window transferred it to "NewMacBookPro".

Why is "NewMacBookPro" showing up as "MacBookPro" in AirDrop? It shows the icon that I use for myself in contacts, originally set up on "MacBookPro", so I suspect it has something to do with sharing contacts, but I don't know why that would override the name in "Sharing". TIA for any suggestions to fix.