I found a theme that had multiple install options, but when I selected one, nothing happened. I had to go Back to the main theme browser (out of the details screen) to get it to install. Reproducible: Always
Confirmed, this is an issue with the old QWidgets dialog.
A possibly relevant merge request was started @ https://invent.kde.org/frameworks/knewstuff/-/merge_requests/14
Git commit f5fd5458d49f0f0b5e5d682fa13f21636f597166 by Alexander Lohnau. Committed on 18/07/2020 at 19:26. Pushed by alex into branch 'master'. Fix details install dropdown in QWidgets dialog FIXED-IN: 5.73 The button was connected to the install slot, but if there is a dropdown the actions get the signal emitted and this signal was not handled. To try this out you can search for "jetbrains" in the dolphin services KNS dialog and go to the details page and install one of the variants. M +10 -2 src/ui/entrydetailsdialog.cpp M +1 -0 src/ui/entrydetailsdialog_p.h https://invent.kde.org/frameworks/knewstuff/commit/f5fd5458d49f0f0b5e5d682fa13f21636f597166