SUMMARY

Discover (plasma-discover) won't start after upgrade to Plasma 6.

STEPS TO REPRODUCE

Just run Discover in any way:
'See updates' menu on taskbar icon or click on icon or run from from console.

OBSERVED RESULT
Nothing happens.

If I run it from the console I get this:

$ plasma-discover
libs QList("/usr/lib/x86_64-linux-gnu/qt6/plugins", "/usr/bin")
org.kde.plasma.libdiscover: OdrsReviewsBackend: Fetch ratings: false
adding empty sources model QStandardItemModel(0x55b68d2d3000)

And that's it.  I can see the process /usr/bin/plasma-discover in the list but app window won't appear.


SOFTWARE/OS VERSIONS

$plasma-discover --version -> discover 6.0.0

Description:    KDE neon 6.0
Release:        22.04
KDE Plasma Version: 6.0.0
KDE Frameworks Version: 6.0.0
QT Version: 6.6.2
Kernel Version: 6.5.0-21-generic (64-bit)
Graphic Platform: Wayland

ADDITIONAL INFORMATION

If I run 'pkcon -v refresh' and 'pkcon update',
it says "No packages require updating to newer versions."
and yet there's 'Update available' icon on taskbar.