This is probably common sense and a topic we've covered numerous times here before. But if you take something you've published and then distribute that content to be republished on other sites or another site, those other sites may rank above you for that piece of content in Google.
As Danny Sullivan from Google said on this topic not too long ago, your best bet is to make your syndication partner canonical back to your original story. If you do not do that, then who knows what will happen that story and which site Google will list in its search results for that story.
John Mueller touched on the topic as well, was a bit more vague - simply because it is hard to know the outcome in general for every specific case:
If you distribute your content and republish it elsewhere, then those other versions can appear in search as well.
— 🍌 John 🍌 (@JohnMu) November 14, 2019
Not necessarily.
— 🍌 John 🍌 (@JohnMu) November 14, 2019
It could be that your site ranks for the piece of content for a given query or it can be that your syndication partner does. It could be query dependent, could be content dependent, could be based on a ton of factors. So it is hard to say.
So be careful with distributing your content for others to republish. Especially when you control it - I mean, if someone just steals your content, then you can take the DMCA route I guess.
Forum discussion at Twitter.