No response to put.show()

After installing Anaconda3(64bit) for windows and entering the following code in spyder, the graph appears on the console when you enter plt.plot(num, heoght), but plt.show() has no new window, no error message, and no response.

import numpy as np
import matplotlib.pyplot asplt
num = np.array ([1, 2, 3, 4, 5])
height = np.array ([100, 300, 200, 500, 400])
plt.plot(num, height)
plt.show()

I checked the version of PyQt at the command prompt and found that PyQt5 was installed and
I also looked at the matplotlib backend configuration and found that it was qt5agg.
Most of the solutions to the problems you find online regarding plt.show() are related to the backend configuration, and I'm at a loss because I can't find anything else to do.

I would appreciate your advice.Thank you for your cooperation.