From the article

The same post talks about some of Facebook’s tactics for bypassing the adblockers. A user in the thread described trying to use uBlock's element picker to block the word "Sponsored" on ads, only to find Facebook splits the word into individual letters, each wrapped in its own line of code. A member of the uBO development team confirmed this isn't new, and that the technique has been in use for roughly five years. They also added that Facebook has at times gone further by randomizing letter order and inserting fake characters to throw off pattern-matching filters.

Facebook splits the text “Ad” in the code so you have an “A” and “d” defined separately and then through some magic make them appear together when rendered… and then they change the exact locations and naming frequently.