Why does my hover keep moving away in Super Mario Maker 2?

One day, I hop onto Super Mario Maker 2, and I am making a regular map.

And then, suddenly, when I place a Goomba on the ground, and leave the hover to get another item, the hover moves after placing it. There is nothing wrong with my Switch, and this is very frequent and common. I was moving the hover with the joystick, so I tried moving it on screen, but that fell flat. The movement the hover went was up, but slowly. There are forums about the hover moving offsite, but it didn’t answer my question. I don’t know where the Super Mario Maker 2 support is anyway.

If possible, can anyone please tell me what is happening and why it is moving?