Allow Users to Edit Ranges feature's Access Permissions (on a domain): Not working?

I've been trying to follow these Microsoft Excel Help & Training instructions

https://support.microsoft.com/en-us/office/lock-or-unlock-specific-areas-of-a-protected-worksheet-75481b72-db8a-4267-8c43-042a5f2cd93a?ui=en-us&rs=en-us&ad=us... but so far, to no avail.

This uses the "Allow Users to Edit Ranges" feature in the Review ribbon.

I'm trying to set up row-level permissions by user account (we're all on a domain) within a single Excel worksheet. (That is, I want to allow users to be able to edit ONLY their own row, using permissions determined from their Windows sign-in to the domain.) I am against setting and sharing passwords (unless maybe everyone could use the same password, and still be allowed to edit only their assigned row).

However, when I complete the tutorial, I can still edit everyone's row -- even though I gave myself permissions to only my row. I'm using the "Protect Worksheet" feature's password to switch between development and testing.

This open question is similar to my results...
Does permissions feature on Allow Users to Edit Ranges work? 

Is this Excel feature broken? Or am I doing something wrong?

An aside: I need help getting this to work manually. Should it start to work... I've already written a fully-functional VBA sub to apply the permissions row-wise using a column containing the username... but first I need the Excel feature's basics to work first in manual!