hreflang tags.

In my Google Search console under International Targeting it says
“Target your audience based on location and language settings. Learn more.
https://www.google.com/support/webmasters/answer/6059209
Language Country
Your site has no hreflang tags.
Google uses hreflang tags to match the user’s language preference to the right variation of your pages.

I don’t know if this is related to this plugin, but it would seem like the obvious location to add this meta tag.

https://www.ads-software.com/plugins/google-language-translator/