Dear Maintainer,

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appropriate ***

   * What led up to the situation?

I just upgraded my Debian testing. This upgraded [UPGRADE]
jupyter-notebook:amd64 6.1.5-1 -> 6.2.0-1. Since this upgrade, the
ctrl-v ctrl-z shortcuts are no more working correctly.
- ctrl-c: seems to correctly work as the selection appears in the KDE
clipboard.
- ctrl-v: only moves the cursor in jupyter notebook to the end of the
current cell, without inserting the copied text.
- ctrl-z: ineffective.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

- These shortcuts correctly work for other web pages (e.g.
www.google.com) so I don't think it's related to chromium or the KDE
clipboard.
- The clipboard works correctly under jupyter with firefox-esr
(78.7.0esr-1).
- I could not revert to jupyter-notebook:amd64 6.1.5-1 as it is no more
available on debian mirrors nor in my /var/cache/apt directory.

Thanks,
Best regards

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