Overview: Default apps part of systemsettings(kcm_componentchooser) doesn't seem to update for the terminal emulator region. How to reproduce: Go to the terminal emulator default applications part of the system settings, click on the ... button, choose any app and the textual region doesn't seem to update.
Happens on KDE Neon, Arch, Manjaro, and Kubuntu as well. It's not limited to only the terminal setting, but all other applications as well.
Related to/duplicate of Bug 394835?
When I choose "terminator" textual region shows just "termina". Plasma 5.14 beta, Arch Linux.
Fixed in Plasma 5.19.