Have you heard of the Smart Matching match type? You might have as it is a bug known since 2021!
Greg Kohler found it in March 2021. Google responded, stating that it was a bug related to a small experiment that select advertisers had opted into, and they were supposedly working on fixing it, as mentioned in the tweet.
Now, in August 2024, Andrea Mejia have seen it again.
It was shared by Adriaan Dekker.