How do I get Zoom to pick up the K sound in isolation?

[educate79]

I teach phonics online, and I found out from my students that when I make the K sound, it doesn't come through. So I started playing with audio settings. Nothing I do fixes this issue. It also does not matter if I use my PC audio or a fancy external microphone. I have even purchased a different PC. 

Now, when I try it on my ipad, it comes through just fine. And when I use another recording software such as screencastify, it works perfectly on my PC. 

So, I am thinking there has to be a setting somewhere, within Zoom, since this is the only application that I have this issue. But I have played and played with the audio settings, and have had 0 success.