Here let Recode (a tech vertical that vox later acquired) explain it.
The campaign placed 88 ads with an obscure concentration camp symbol on them.
https://www.vox.com/recode/2020/6/18/21295226/facebook-trump-campaign-nazi-symbol-antifa
Maybe it was a mistake doing 30 pages here, 30 pages another place, and 28 places a 3rd place in a single ad buy ... maybe ... but it doesn't past the smell test to my nose.
Not saying Trump himself did this, for a campaign is something with a couple hundred workers, yet 1 person did pull out the credit card and make choices of what Trump put on other people's feed for that is how advertising works. I put things in your feed without you signaling I want more of this, I get to do this for I have money and I pay Facebook the middle man..