SUMMARY
I was setting up the flatpak OBS studio via their initial wizard. A notification appeared that said OBS has some access to something, but it has not provided valid reason. I clicked Allow and then xdg-desktop-portal-kde crashed.

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 21.04
KDE Plasma Version: 5.21.90
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-17-lowlatency (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 7,6 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620

Application: xdg-desktop-portal-kde (xdg-desktop-portal-kde), signal: Segmentation fault

[KCrash Handler]
#4  std::__atomic_base<int>::load (__m=std::memory_order_relaxed, this=<error reading variable: Cannot access memory at address 0x88>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qrefcount.h:54
#5  QAtomicOps<int>::loadRelaxed<int> (_q_value=<error reading variable: Cannot access memory at address 0x88>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qatomic_cxx11.h:239
#6  QBasicAtomicInteger<int>::loadRelaxed (this=<error reading variable: Cannot access memory at address 0x88>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qbasicatomic.h:107
#7  QtPrivate::RefCount::ref (this=<error reading variable: Cannot access memory at address 0x88>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qrefcount.h:55
#8  QMap<QString, QVariant>::QMap (other=..., this=0x7ffe656745e0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qmap.h:627
#9  KNotification::hints (this=this@entry=0x55a3d4dc4b70) at ./src/knotification.cpp:598
#10 0x00007fd4234fde06 in KNotificationManager::notificationActivated (this=0x7fd42352e060 <(anonymous namespace)::Q_QGS_s_self::innerFunction()::holder>, id=<optimized out>, action=1701266920) at ./src/knotificationmanager.cpp:239
#11 0x00007fd4211a6b0e in QtPrivate::QSlotObjectBase::call (a=0x7ffe65674760, r=0x7fd42352e060 <(anonymous namespace)::Q_QGS_s_self::innerFunction()::holder>, this=0x55a3d4d52490) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#12 doActivate<false> (sender=0x55a3d4d909d0, signal_index=4, argv=argv@entry=0x7ffe65674760) at kernel/qobject.cpp:3886
#13 0x00007fd42119fcb8 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fd42352c6c0 <KNotificationPlugin::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7ffe65674760) at kernel/qobject.cpp:3946
#14 0x00007fd4234f87a3 in KNotificationPlugin::actionInvoked (this=<optimized out>, _t1=<optimized out>, _t2=<optimized out>) at ./obj-x86_64-linux-gnu/src/KF5Notifications_autogen/EWIEGA46WW/moc_knotificationplugin.cpp:167
#15 0x00007fd42350ec3b in NotifyByPopup::onNotificationActionInvoked (this=0x55a3d4d909d0, notificationId=2, actionKey=...) at ./src/notifybypopup.cpp:112
#16 0x00007fd4211a6b0e in QtPrivate::QSlotObjectBase::call (a=0x7ffe65674990, r=0x55a3d4d909d0, this=0x7fd414007bc0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#17 doActivate<false> (sender=0x55a3d4d90a08, signal_index=3, argv=argv@entry=0x7ffe65674990) at kernel/qobject.cpp:3886
#18 0x00007fd42119fcb8 in QMetaObject::activate (sender=<optimized out>, m=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffe65674990) at kernel/qobject.cpp:3946
#19 0x00007fd423519efd in OrgFreedesktopNotificationsInterface::ActionInvoked (_t2=..., _t1=<optimized out>, this=<optimized out>) at ./obj-x86_64-linux-gnu/src/notifications_interface.moc:213
#20 OrgFreedesktopNotificationsInterface::qt_static_metacall (_o=_o@entry=0x55a3d4d90a08, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=0, _a=_a@entry=0x7ffe65674ad0) at ./obj-x86_64-linux-gnu/src/notifications_interface.moc:128
#21 0x00007fd42351a3b3 in OrgFreedesktopNotificationsInterface::qt_metacall (this=0x55a3d4d90a08, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7ffe65674ad0) at ./obj-x86_64-linux-gnu/src/notifications_interface.moc:199
#22 0x00007fd421434359 in QDBusConnectionPrivate::deliverCall (this=<optimized out>, object=<optimized out>, msg=..., metaTypes=..., slotIdx=<optimized out>) at ../../include/QtCore/../../src/corelib/tools/qvarlengtharray.h:201
#23 0x00007fd42119c2a1 in QObject::event (this=0x55a3d4d90a08, e=0x7fd414010b40) at kernel/qobject.cpp:1314
#24 0x00007fd4229f8173 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x55a3d4d90a08, e=0x7fd414010b40) at kernel/qapplication.cpp:3632
#25 0x00007fd42116f22a in QCoreApplication::notifyInternal2 (receiver=0x55a3d4d90a08, event=0x7fd414010b40) at kernel/qcoreapplication.cpp:1063
#26 0x00007fd421171d01 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x55a3d4cdf940) at kernel/qcoreapplication.cpp:1817
#27 0x00007fd4211c8f37 in postEventSourceDispatch (s=0x55a3d4d580c0) at kernel/qeventdispatcher_glib.cpp:277
#28 0x00007fd41f75c8eb in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fd41f7afd28 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fd41f75a023 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007fd4211c8594 in QEventDispatcherGlib::processEvents (this=0x55a3d4d58140, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#32 0x00007fd42116db8b in QEventLoop::exec (this=this@entry=0x7ffe65674f10, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#33 0x00007fd421176024 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#34 0x00007fd421d9ccb0 in QGuiApplication::exec () at kernel/qguiapplication.cpp:1867
#35 0x00007fd4229f80e9 in QApplication::exec () at kernel/qapplication.cpp:2824
#36 0x000055a3d341ee87 in main (argc=<optimized out>, argv=<optimized out>) at ./src/xdg-desktop-portal-kde.cpp:39
[Inferior 1 (process 19540) detached]