This seems to consistently cause Discover to crash on startup. The coredump can be found at https://openqa.fedoraproject.org/tests/3152598/file/desktop_update_graphical-coredump.tar.gz , but I can't seem to get a successful backtrace out of it. System logs say:

Jan 19 07:40:46 fedora plasma-discover[2462]: org.kde.plasma.libdiscover: OdrsReviewsBackend: Fetch ratings: true
Jan 19 07:40:46 fedora plasma-discover[2462]: adding empty sources model QStandardItemModel(0x5588aa463320)
Jan 19 07:40:46 fedora systemd[1]: Starting flatpak-system-helper.service - flatpak system helper...
Jan 19 07:40:46 fedora audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=flatpak-system-helper comm="systemd" exe="/usr/li>
Jan 19 07:40:46 fedora systemd[1]: Started flatpak-system-helper.service - flatpak system helper.
Jan 19 07:40:47 fedora plasma-discover[2462]: qrc:/qt/qml/org/kde/discover/qml/BrowsingPage.qml:17:1: QML BrowsingPage: Created graphical object was not placed in the graphics scene.
Jan 19 07:40:47 fedora plasma-discover[2462]: KCrash: Application 'plasma-discover' crashing... crashRecursionCounter = 2
Jan 19 07:40:47 fedora audit[2462]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=2462 comm="plasma-discover" exe="/usr/>
Jan 19 07:40:47 fedora systemd-coredump[2510]: Process 2462 (plasma-discover) of user 1000 terminated abnormally with signal 11/SEGV, processing...