As shown in the screenshot below, there's a problem on macOS where strange special characters (a kite? a box? a hanafuda card?) appear when typing Korean in Chromium-based browsers. They're invisible while you're writing in Chrome, but they show up in Safari or on Windows. This becomes an awkward situation when you're writing a document meant for public consumption.
Here's how to fix it.
- In Safari, the special characters are visible as-is. So do one more review pass in Safari and delete them.
- Use
Gureum input method.
Source: https://discussionskorea.apple.com/thread/254883494?sortBy=best