I’m running KDE Plasma Version 5.27.8 on Fedora 38. It’s been very stable and Plasma crashes a lot less comparing to the old day when running Plasma 5.0 on (older) Kubuntu.
Anyway, today, my Plasma’s taskbar froze and I needed to restarted. Instead of logging out and logging back in, I found a way to restart the Plasmashell. Here is the command which worked for me for this Plasma version:
➜ killall plasmashell ; kstart plasmashell
Full credit goes to the link in the reference below.