Old admin account name, not current name, shows up in Task Scheduler

I set up a new computer with an MS admin account named X. For business reasons, I decided to change the name to Y (X and Y are placeholders). I did this through my MS account. I also changed the account to a local account. Everything looked fine. Until I decided to create a task in Task Scheduler. For some reason, TS assigned this task to user X. I clicked the "Change the User or Group…" button and typed the new user name Y, but clicking Check Names displays a message that "the following name cannot be found: 'Y' ".
How can I get TS to register the user as Y?

In users folders what name shows up there if you rename a user it often keeps the old name