I had this issue, and found almost exactly the same problem on Stack Overflow (link)

Briefly, the pyplot.legend does not try to avoid pyplot.text. Here is a minimal example:

import matplotlib.pyplot as plt
x = [1, 2]
plt.plot(x, x, label='plot name')
plt.gca().text(0.05, 0.95, 'some text', transform=plt.gca().transAxes, verticalalignment='top')
plt.gca().legend(loc='best')
plt.show()

resulting in legend overlaying the text like this:

BTW, my matplotlib version is 3.4.3