Getting weird results with negative keywords…

Does anyone else have experience with this?

I have negative keywords set up at the campaign and ad group level. I have them set up as both a negative phrase and negative exact. For example, negative keyword “bank teller” as both negative phrase and negative exact.

Despite this, my ads are still appearing in searches for the negative keyword. In other words, my ads are appearing when someone searches on Amazon for “bank teller.”

I can’t figure out why this is happening. Am I paying for the appearance of my sponsored ads? Is this something that Amazon is just doing at its own discretion. Have I set something up incorrectly with my campaign?

Any thoughts/suggestions are appreciated. Amazon says that this can’t be happening, but yet, it is occurring.