SUMMARY
I normally wear headphones, but when I turn on my A/V receiver, which takes my computer's HDMI output, plasmashell gets tough to respond before it dies out.


STEPS TO REPRODUCE
1. Turn on A/V receiver.

OBSERVED RESULT
Plasmashell is tough to respond because it is so busy.
There's a lot of I/O with plasmashell and kioslave5.
The journal gets flooded with kioslave5 entries mentioned in the title.
Eventually plasmashell dies out because a long time ago I set a systemd --user memory limit because it kept leaking.
Once it restarts, things settle down.

EXPECTED RESULT
Normal usage.


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
I've even encountered a case where plasmashell constantly respawned. I increased the memory limit to 600MB (from 500MB).
While it was flooding the log before dying out, I got a backtrace of kioslave5.
******
0x00007f9f0a4b2ad6 in ppoll () from /usr/lib/libc.so.6
(gdb) bt
#0  0x00007f9f0a4b2ad6 in ppoll () from /usr/lib/libc.so.6
#1  0x00007f9f0a870d0b in qt_safe_poll(pollfd*, unsigned long, timespec const*) () from /usr/lib/libQt5Core.so.5
#2  0x00007f9f0a2971a4 in ?? () from /usr/lib/libQt5Network.so.5
#3  0x00007f9f0a2988d6 in ?? () from /usr/lib/libQt5Network.so.5
#4  0x00007f9f0a285eb7 in QAbstractSocket::waitForReadyRead(int) () from /usr/lib/libQt5Network.so.5
#5  0x00007f9f0ab10dfa in ?? () from /usr/lib/libKF5KIOCore.so.5
#6  0x00007f9f0ab4524a in KIO::SlaveBase::dispatchLoop() () from /usr/lib/libKF5KIOCore.so.5
#7  0x00007f9f0ac5e514 in kdemain () from /usr/lib/qt/plugins/kf5/kio/desktop.so
#8  0x0000564316096207 in ?? ()
#9  0x00007f9f0a3db790 in ?? () from /usr/lib/libc.so.6
#10 0x00007f9f0a3db84a in __libc_start_main () from /usr/lib/libc.so.6
#11 0x0000564316096465 in ?? ()
******