Description of problem:
I tried sharing multiple files from my smartphone to my PC. It repeatedly did not finish but got stuck in the progress bar.

Steps I followed:
1. On my smartphone, open the file manager
2. Select multiple files (5…50 files, 1…500MB) and click the "Share" button
3. Select KDE connect and share with my PC
4. When KDE connect progress bar is stuck, click "Abbrechen" ("Abort"?)

What happens:
The first few files were transferred just fine. At some point, the progress bar in KDE connect's window on my PC got stuck. KDE connect on the Smartphone seemed to continue sending files (progress bar continued as if everything were fine), finishing in regular expected time, but the files were not stored on my PC.
After I pressed "Abbrechen", it seems like KDE connect crashed (tray icon vanished). I'm not sure however whether this crash report was happening at the time the transfer got stuck or whether it was happening at the time KDE connect's tray icon vanished.

What should happen:
File transfer should not get stuck. KDE connect should not crash when aborting stuck file transfer.

How reproducible:
It seems like this issue happens more likely the more files (or larger files?) I transfer. With 10 files of at least 100MB, I could reproduce it 100%.

Software and versions:
My smartphone is running Android 12 and KDE connect 1.27.0. I shared the files with "Simple File Manager" (see https://github.com/SimpleMobileTools/Simple-File-Manager ).

Additional comments:
At the same time, something weird happened with my Wifi router (Fritz!Box 7520, Fritz!OS 7.50): It seemed to crash somehow, disconnecting from the internet but still reacting to ping.

Version-Release number of selected component:
kdeconnectd-23.04.3-2.fc38

Additional info:
reporter:       libreport-2.17.11
type:           CCpp
reason:         kdeconnectd killed by SIGABRT
journald_cursor: s=c13f6a5aaaaa4f56b87e84b483d36f17;i=8f9c6;b=468166f4b8d5405ab1d1115d38514443;m=7623696a;t=6019ad9ad0e14;x=e51177e9bc4cf0ec
executable:     /usr/libexec/kdeconnectd
cmdline:        /usr/libexec/kdeconnectd
rootdir:        /
kernel:         6.4.6-200.fc38.x86_64
package:        kdeconnectd-23.04.3-2.fc38
runlevel:       N 5
backtrace_rating: 4
crash_function: qt_message_fatal

Truncated backtrace:
Thread no. 1 (11 frames)
 #4 qt_message_fatal at global/qlogging.cpp:1914
 #6 KIO::SlaveBase::waitForAnswer(int, int, QByteArray&, int*) at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/core/slavebase.cpp:1149
 #7 KIO::SlaveBase::canResume(unsigned long long) at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/core/slavebase.cpp:1116
 #8 FileProtocol::put(QUrl const&, int, QFlags<KIO::JobFlag>) at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/ioslaves/file/file.cpp:550
 #9 KIO::SlaveBase::dispatch(int, QByteArray const&) at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/core/slavebase.cpp:1289
 #10 KIO::SlaveBase::dispatchLoop() at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/core/slavebase.cpp:342
 #11 KIO::WorkerThread::run() at /usr/src/debug/kf5-kio-5.108.0-1.fc38.x86_64/src/core/workerthread.cpp:62
 #12 operator() at thread/qthread_unix.cpp:350
 #13 (anonymous namespace)::terminate_on_exception<QThreadPrivate::start(void*)::<lambda()> > at thread/qthread_unix.cpp:287
 #14 QThreadPrivate::start(void*) at thread/qthread_unix.cpp:310
 #16 clone3 at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81