[BUG] In a multi-line CSV file, a row disappear when a line break occurs.

[EngYOSHI]

Thank you for this project.

While editing a cell, when I insert a line break using Shift + Enter, the row I had been entering disappears.
After it disappears, I am able to insert a line break in that row, but the same issue occurs in subsequent rows as well—on the first line break attempt, the row always disappears.

I have included a reproduction video below.
https://github.com/user-attachments/assets/3608323d-7f61-4621-b8f3-9700e5da5c14

Thank you in advance.

[EngYOSHI]

Additional information:
This issue occurs not only when pressing Shift + Enter, but also when saving the file (Ctrl + S or via File → Save).

For example: type “aaaa”, press Shift + Enter to insert a new line, type “bbbb”, then press Ctrl + S. As a result, “bbbb” disappears.