SUMMARY
Demonstrative video: https://youtu.be/NP7jhyzO4vg
Sometimes when disconnecting an USB stick using the GUI, it crashes the shell. This does not happen every time so you may need to try plugging and unplugging the stick physically multiple times.

STEPS TO REPRODUCE
1. Repeatedly mount and unmount an USB stick through the GUI

OBSERVED RESULT
Sometimes the plasmashell crashes

EXPECTED RESULT
No crash should happen

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.23.2
KDE Frameworks Version: 5.87.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Backtrace:
#0  0x00007f01a4167d22 in raise () at /usr/lib/libc.so.6
#1  0x00007f01a662a064 in KCrash::defaultCrashHandler(int) () at /usr/lib/libKF5Crash.so.5
#2  0x00007f01a4167da0 in <signal handler called> () at /usr/lib/libc.so.6
#3  std::__atomic_base<QThreadData*>::load(std::memory_order) const (__m=std::memory_order_relaxed, this=<error reading variable: Cannot access memory at address 0x8>)
    at /usr/include/c++/11.1.0/bits/atomic_base.h:836
#4  std::atomic<QThreadData*>::load(std::memory_order) const (__m=std::memory_order_relaxed, this=<error reading variable: Cannot access memory at address 0x8>) at /usr/include/c++/11.1.0/atomic:570
#5  QAtomicOps<QThreadData*>::loadRelaxed<QThreadData*>(std::atomic<QThreadData*> const&) (_q_value=<error reading variable: Cannot access memory at address 0x8>) at /usr/include/qt/QtCore/qatomic_cxx11.h:239
#6  QBasicAtomicPointer<QThreadData>::loadRelaxed() const (this=<error reading variable: Cannot access memory at address 0x8>) at /usr/include/qt/QtCore/qbasicatomic.h:248
#7  QQmlNotifierEndpoint::connect(QObject*, int, QQmlEngine*, bool) (this=this@entry=0x5557906804d0, source=0x555790817e30, sourceSignal=46, engine=0x0, doNotify=doNotify@entry=true)
    at /usr/src/debug/qtdeclarative/src/qml/qml/qqmlnotifier.cpp:122
#8  0x00007f01a5cdf7d7 in QQmlVMEMetaObjectEndpoint::tryConnect() (this=0x5557906804d0) at /usr/src/debug/qtdeclarative/src/qml/qml/qqmlvmemetaobject.cpp:258
#9  0x00007f01a5cdfa78 in QQmlVMEMetaObject::connectAlias(int) (this=this@entry=0x555790627460, aliasId=aliasId@entry=1) at /usr/src/debug/qtdeclarative/src/qml/qml/qqmlvmemetaobject.cpp:1294
#10 0x00007f01a5ce10ab in QQmlVMEMetaObject::metaCall(QObject*, QMetaObject::Call, int, void**) (this=0x555790627460, o=<optimized out>, c=QMetaObject::ReadProperty, _id=<optimized out>, a=0x7fffcf3266c0)
    at /usr/src/debug/qtdeclarative/src/qml/qml/qqmlvmemetaobject.cpp:906
#11 0x00007f01a5c12e55 in QQmlPropertyData::readProperty(QObject*, void*) const (property=0x7fffcf3266a0, target=<optimized out>, this=0x7f018c6c6c58)
    at ../../include/QtQml/5.15.2/QtQml/private/../../../../../../qtdeclarative/src/qml/qml/qqmlpropertydata_p.h:357
#12 loadProperty(QV4::ExecutionEngine*, QObject*, QQmlPropertyData const&) (v4=0x55578b725010, object=0x5557904fb180, property=...) at /usr/src/debug/qtdeclarative/src/qml/jsruntime/qv4qobjectwrapper.cpp:152
#13 0x00007f01567db2d3 in  ()
#14 0x0000000000000000 in  ()