yapf-diff inconsistent with yapf on multiline strings with backslashes

[marcodicro-dp]

If I run yapf over my files, yapf says all is good.

But I run yapf-diff over my PR diff, yapf-diff is generating some unexpected auto-format changes, with lots of unnecessary spaces:

File 1

File 2

Could this be a specific bug related to multiline strings that use backlashes?

Note: My PR has over a thousand files and these were the only unexpected yapf-diff changes.