Bug summary

Using the QT5Agg backend with the 3.5.1 version of Matplotlib crashes after pressing 'ok' in the Figure Options GUI. This happens regardless of doing any changes to the plot or not.
The only way to bring Matplotlib back to life, is to restart the python kernel.

Code for reproduction

import matplotlib.pyplot as plt
plt.plot([1,2],[1,2])

# Then open Figure Options, and press 'ok'

Actual outcome

Plot window becomes inactive, and does not response to any input.

Expected outcome

No changes to the plot window whatsoever. The window should continue being responsive.

Additional information

I am running my scripts in Spyder, which is where I am experiencing this bug.

Operating system

Windows 10

Matplotlib Version

3.5.1

Matplotlib Backend

Qt5Agg

Python version

3.9.10

Jupyter version

No response

Installation

conda