Glass display bends when I write with apple pencil

I just received my iPad that I ordered a few weeks ago and have been writing with the apple pencil for the past hour or so. And while I was writing, I noticed that the glass display keeps slightly bending (moving up and down) as I'm writing. It's as if the screen isn't hard enough so when I apply pressure, the screen slightly bends. I'm not sure if it's because I'm pressing too hard or if it's a problem of my iPad. I tried writing with less pressure and tried not to press the screen too much, but I do still notice a slight movement in the screen and it is pretty bothersome when I write. Has anyone experienced the same problem or does this mean there's something wrong with my iPad?