Cannot login using username + password on GitHub-created account

[a-ws-m]

Describe the bug
If you add a password to an account you have created using GitHub login, you cannot login using that username and password. Instead, you will be redirected to GitHub login after you press the "login" button.

I have tested this on both desktop and mobile.

To Reproduce
Steps to reproduce the behavior:

1. Create an account using GitHub login option.
2. Go to Account Settings and change your password.
3. Clear cache and login using username and password.

Expected behavior
Using the username and password should immediately login -- there should be no need to login to GitHub.

Desktop (please complete the following information):

• OS: Windows 10
• Browser: Firefox
• Version: 126.0.1

Smartphone (please complete the following information):

• Device: OnePlus 7 Pro
• OS: Android 12
• Browser: DuckDuckGo
• Version 5.202.0

Additional context

Although it seems minor, this is important for 3rd party applications. I am also unable to link other OAuth accounts to the one I created using GitHub, which means I cannot login to my account using e.g. https://github.com/acristescu/OnlineGo (only options are to login with username + password or Google).