Bug report

Try any of the wx examples that update the plot (such as the button in embedding_in_wx4_sgskip.py), and the plots don't update until you do something to them outside of the fig.canvas.draw, such as starting a pan/zoom or resizing.

Matplotlib version

• Operating system: Fedora 34
• Matplotlib version (import matplotlib; print(matplotlib.__version__)): master
• Matplotlib backend (print(matplotlib.get_backend())): wxAgg
• Python version: 3.9
• Jupyter version (if applicable):
• Other libraries: