Can't find keywords

Hey, y'all. I have a quick question. Would really appreciate your help.

So, I was looking for some keywords on the topic of "NFT + Tax" on Mangools. But it's showing no results. It says "make sure you're not researching sensitive keywords. But I don't understand. NFT isn't a sensitive keyword for sure, and I don't why tax would be.

Is it really a problem of sensitive keywords or is it something else I'm missing?

And is there any solution to this?