Am I buggin or is this normal?

[still ember]

Recently ive been noticing some weird shit with my builds, and today i managed to catch the exact moment of it. On that mouse button i have a floor bind. At the start of the video im holding that button but on the screen its showing a wall, my previous build. I press the SAME BUTTON again and then its a floor. Basically it sometimes either doesnt register the button press or smth idk. Is there a possibility that this is a game issue or a mouse one?