Unnatural cursor moves when truncate-lines is nil

[takemaru]

Thank you for developing this great tool.

When truncate-lines is nil, the cursor moves up and down unnaturally on lines marked as changed or added.

• Moving down a text that contains a long wrapped line causes the cursor to take one step to the right and back (like a soccer player feinting).
• Conversely, moving up the text causes the cursor to jump to the upper right instead of directly above.

As the attached video shows, even if I only press the down or up key, the cursor moves to the right.

Thank you in advance.

https://user-images.githubusercontent.com/376562/228699070-c8d808bb-5930-4eab-b590-cf447844235d.mov