Does falling count as movement?

So, the question I have is I’m planning to play a Sun Soul Arrakocra monk. With the flight of the Arrakocra I can essentially hit someone, fly up and repeat. So what I want to ask is let’s say I fly up 50 feet and I just decide to drop to the ground. Do the 50 feet drop count against my movement or no? Is there any rules that specify that so I can justify it to my DM. Thanks and regards, Ichmkami