I suppose that is another possible solution - delete the autologin user.  However, I have a bad feeling about that solution ;-)

Here’s part of the reason why:

Before you delete that user, make sure that your new admin user (which is to say, a user in the adm group) has all sudo (probably still with password) permissions….  You don’t want to end up with a machine that you have to boot on a live DVD in order to become root!

From: PLUG-discuss [mailto:plug-discuss-bounces@lists.phxlinux.org] On Behalf Of Stephen Partington
Sent: Thursday, June 21, 2018 7:42 AM
To: Main PLUG discussion list
Subject: Re: Mint Cinnamon with a default login

I would suggest that you create a new Admin user, Log in as that user and verify it works. Delete the Company create user.

Disabling the automatic login has several paths to execution. https://unix.stackexchange.com/questions/45573/how-to-disable-auto-login-in-linux-mint