Inconsistent Username Validation: Spaces Allowed on Sign Up but Not on Sign In

[cyrisky]

Describe the bug
When I first sign up, the form allows me to input a username with spaces. However, during sign-in, the system does not accept usernames with spaces, causing a mismatch and login failure.

To Reproduce

1. Steps to reproduce the behavior:
2. Go to the Sign Up page.
3. Enter a username with spaces (e.g., john doe) and complete the registration.
4. Go to the Sign In page.
5. Try signing in with the same username (john doe).
6. See error — login fails due to invalid username format.

Expected behavior
Usernames should be validated consistently across both Sign Up and Sign In forms. If spaces are not allowed, the Sign Up form should prevent them or normalize input accordingly.

Screenshots

Desktop (please complete the following information):

• OS: Sequoia 15.3.1
• Browser Chrome
• Version 135.0.7049.85

[joanpot]

As a workaround, at login, type the name without spaces and then move the cursor back and add the spaces.

[MaxDevNix]

It doesn't affect just usernames, it affects passwords too.