Light mode does not work in New Yahoo Mail

Since my account was forced to switch to the New Yahoo Mail, the mailbox remains in Dark Mode even when I select Settings → Appearance → Light.

The Settings panel itself correctly changes between Light and Dark, but when I return to the mailbox/inbox, the mailbox remains black.

I have tested this on two completely different computers:

• Mac with Safari — Yahoo Mail remains dark even when macOS Appearance is set to Light.
• Windows PC with a light system theme — Yahoo Mail also remains dark.
• I also tested Automatic mode on the Windows PC. The system is set to a light theme, but Yahoo Mail still remains dark.

I refreshed the mailbox after changing the settings, as instructed in Yahoo Help. The problem remains.

This therefore appears to be an account-specific or New Yahoo Mail interface issue rather than a browser or operating-system setting.

The dark mailbox also makes it very difficult to distinguish read messages from unread messages, which seriously affects the usability of the inbox.

Please fix the Light/Dark Mode setting so that selecting Light actually displays the mailbox in Light Mode.

Thank you.