At present I have two computers running remote desktop application NoMachine. Coincidentally, the computers are connected for file sharing with Samba; they, in turn, are connected to two other computers, also using Samba. While I cannot login to the computer (which I was viewing from my main computer), the other computers can see and access folders and files on it. Here’s what happened: I rebooted the computer I was viewing while I was viewing it for the first time with NoMachine. (Apparently, that should not be done.) Just prior to this, I had added a Samba user for file transfer purposes; so a second person could backup files on the computer in question. Now that username and name show up (as separate boxes) along with my own and a couple of other options, including Samba guest account. I have never seen this screen before. And the Mint 19.3 computer in question was set to auto login, which it previously did. I have unplugged and restarted it, to no avail.