Hi Luoqian! Can you confirm if this is happening in the browser, the desktop app, or both?

As a first step, please make sure your operating system and browser are up to date. I’d also suggest force-quitting and reopening Figma to see if that helps.

If the issue persists, please reach out to our support team by submitting this bug report here.
In the form, use your Figma account email, and if possible include a short video showing the issue. You can also add support-share@figma.com as an Editor to the File in the video (this won't affect your billing) and share a link of your file so they can take a closer look. Thanks!