Empty Error Message When Changing Username

Summary

When attempting to change the username for an account from .....- to ..-, it fails to take effect and no error appears in the banner.

Steps to reproduce

  1. Create an account with a username like .....-.
  2. Attempt to change to ..-, .-, or some other variation.

What is the current bug behavior?

Username is changed and the error banner is empty.

What is the expected correct behavior?

Username changed or an error displayed.

Relevant logs and/or screenshots

Account___User_Settings___GitLab

Account___User_Settings___GitLab

Output of checks

This bug happens on GitLab.com