SEO plugin brought google’s Site Traffic down

I had installed the Yoast SEO plugin. Afterwards, an Editor I work with said that she saw google’s Site Traffic had a significant dip. After turning back to the old All in One SEO plugin, we had been using, everything went back to normal.

I had noticed that when I first installed Yoast it gave a warning that Yoast has it’s own Sitemap that might conflict with the Sitemap plugin that we had been using…So I turned Yoast’s sitemap off, but do you guys think that might have still been a conflict? Just trying to figure out if this might have been a temporary thing…or if it’s just not worth it for me to use this plugin and stick with All in One. Any advice / tips are welcome. Thank you!