Bug Report: Sudden failure of OneNote Web automatic color rendering

Context:
    OS: Mac OS
    Web Browser: Google Chrome
    Color Theme/Mode: Dark Mode (across OS, browser, and apps where available)

OneNote for the web has suddenly started failing to properly display automatic color.

For a long time, I've used OneNote across web, desktop, and mobile. For desktop and mobile I've enjoyed dark mode color theme. For web, and explicit dark mode setting has not been available — and the system/browser dark mode setting has had no effect. Normal text, (especially one whose color is set to "automatic" by default), it would always render properly across all the environments, including the effectively light mode web and dark mode desktop/mobile.

Since a few days ago, the OneNote web has developed a weird bug. On one hand, the UI elements have turned dark (as if dark mode was available and enabled). On the other hand, the actual notes area has a background that appears white — while the (automatically colored) text color appears very light gray — practically invisible.

It's as if OneNote web went through a partial dark mode transformation. UI has dark mode, notes background is in light mode, yet the actual text behaves as if it's also in dark mode. The light-on-light text then is effectively invisible.

Desktop and mobile apps work fine. Bug appears on a different browser (Mozilla Firefox; mode=dark) as well. Bug has been reported to customer support and confirmed as internally logged.