The ranking bug introduced what Yoast calls, “Panda-like problems” when it updated to the 7.0 version. This change affected settings to the way image redirects are handled. Fortunately this update did not affect all users.
Here is how Yoast describes the technical problem:
The bug was simple yet very painful: when you updated from an earlier version of Yoast SEO to Yoast SEO 7.0-7.0.2 (specifically those versions), we would not always correctly convert the setting you had for the old setting into the new one. We accidentally set the setting to ‘no’. Because we overwrote the old settings during the update, we could not revert this bug later on.