user is not displayed on login screen after changing its UID
Solution 1:
Setting up UID 1000 in macOS will not show the profile at the log-in window. So, to fix the issue, you have to put other number such as 1001.
You can find more details: https://www.cnet.com/tech/computing/how-to-hide-user-accounts-from-the-log-in-window-in-os-x/