In some cases, the answer's content in "edit answer" page disappears

[fenbox]

To Reproduce

Steps to reproduce the behavior:

1. On the question page, click "Edit" under a specific answer.
2. Go to the editing page, don't make any changes, just click "Cancel".
3. Go back to the question details page, click "Edit" under the same answer again.
4. Go to the editing page, and the main content disappears.

Expected behavior

In step 4, the answer's content should be displayed in the main text.

Platform (please complete the following information):

• Browser Chrome
• Version 1.2.1