[Python] How can i get the output to print 10 circles instead of 9 in python turtle module

I'm trying to figure out why my painting is not having the desired final outcome. As you can see, the first row is printing 10 circles but then the following rows are only printing 9. Have a look at my code, and the attached image.

from turtle import Turtle, Screen
import turtle
import random

colours = [(232, 251, 242), (198, 12, 32), (250, 237, 17), (39, 76, 189),
(38, 217, 68), (238, 227, 5), (229, 159, 46), (27, 40, 157), (215, 74, 12), (15, 154, 16),
(199, 14, 10), (242, 246, 252), (243, 33, 165), (229, 17, 121), (73, 9, 31), (60, 14, 8)]

turtle.colormode(255)

dot = Turtle()
dot.color(255,255,255) # Hide turtle trail
dot.setposition(-270, -350) # Starting position
dot.pensize(21)
dot.shape("circle")
dot.speed(60)

ypos = dot.ycor() # Y coordinates

for cycle in range(1, 11): # Cycles nested forloop 10 times

for num in range(1, 11): # Create 10 circles
dot.showturtle()
dot.color(random.choice(colours))
dot.forward(1)
dot.penup()
dot.forward(50)
dot.pendown()

dot.penup()
dot.sety((ypos + 40*cycle)) # moves turtle up one row with each iteration
dot.setx(-270) # Sets the turtle to starting X coordinate with each iteration

dot.hideturtle()

screen = Screen()
screen.exitonclick()


This is the output, as you can see the bottom row prints 10 circles which is what i want, however the following rows above only print 9 circles

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