After upgrading to recent versions ofjupyterlab,ipympl andipykernel I observed on different systems, either Windows 11 or Linux, thatipympl figures would not show up sometimes without an explicitplt.show() at the end of the cell.

While this looked to me at first glance like anipympl bug because it does not appear using inline figures it turns out that downgradingipykernel to6.3.1 completely solves the issue.

Here is the the original report with more details:matplotlib/ipympl#609

I saw thatipykernel>=7 has quite a few changes regardingmatplotlib, so I assume this is a unwanted side-effect of these changes.