Apparently this is gnome-bug
https://bugzilla.gnome.org/show_bug.cgi?id=780348 that was supposedly
fixed six days ago by commit ace15f5dceaa1691f9aee21f960c281e8c4d9fcc,
but the behaviour is still happening as of today.
** Bug watch added: GNOME Bug Tracker #780348
Public bug reported:
Calculator key doesn't launch the calculator in Zesty
** Affects: gnome-settings-daemon (Ubuntu)
Importance: Undecided
Status: New
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