虽然这个问题是老问题，但我刚刚面对同样的问题并解决了它。
问题是在将面片添加到轴后，您需要在显示参考框架中给予坐标/点。这可以通过以下方式执行：

ax.transData.transform()

我在代码中添加了一行忽略import语句的代码，代码如下所示：

import matplotlib.pyplot as plt
import matplotlib.patches as patches

fig, ax = plt.subplots()
rect = patches.Rectangle([0.2, 0.3], 0.8, 0.5)

pnt = [0.4, 0.45] # point inside rect
print("Before adding patch to axes:")
print(rect.get_path().vertices)
print(rect.contains_point(pnt))
print(rect.get_path().contains_point(pnt))

print("After adding patch to axes")
ax.add_patch(rect)
print(rect.get_path().vertices)
# added lines
pnt_in_display_coordiantes = ax.transData.transform(pnt)
print(rect.contains_point(pnt_in_display_coordiantes))
print(rect.get_path().contains_point(pnt))

plt.show()

输出量：

Before adding patch to axes:
[[0. 0.]
[1. 0.]
[1. 1.]
[0. 1.]
[0. 0.]]
True
True
After adding patch to axes
[[0. 0.]
[1. 0.]
[1. 1.]
[0. 1.]
[0. 0.]]
True
True

更多信息：https://matplotlib.org/stable/tutorials/advanced/transforms_tutorial.html