2017 recommends the following plugin – Notice

I don’t see that in mine.

Have you seen that recommendation before? I’m thinking it could be from other theme and maybe the message is cached.

Yes, I now have seen it on another site using a different theme. So I don’t think it’s 2017 theme specific.
I noticed this during the recent updates.

Trying to replicate this on a test location hasn’t been successful. I wonder if it’s triggered somehow?

I’ll take a guess and say it’s from the Elementor Plugin – both sites are using it and the recommendation is related to Elementor (though it’s a different dev)

Thanks.

Try deactivating all of your plugins to explore whether any could be responsible. If none are, keep all plugins deactivated and switch to the Twenty Seventeen theme to check whether it’s an issue with your theme.