Two actions, "Select Transition" and "Add Subtitle" has the same shortcut - Shift++ Add Subtitle wins, probably it is added last, and there is no shortcut for select transition.
This issue har appearently gone. Add Subtitle have now Shift + S, and select transition has Shift + +. But it does not work - maybe because there is no such thing as a transition any longer? In that case, the related actions should be removed. Otherwise something else went wrong.
Thank you for reporting. Jump with alt + arrow to a composition and use shift + + to select the composition. With shortcut + you can select a clip. What is not working is to select a transition of a same-track-transition (mix). So it's a bug. I updated the bug title accordingly.
Git commit e1cd395adb4741a8b9610e6bf91bf523bb418325 by Julius Künzel. Committed on 15/11/2021 at 23:17. Pushed by jlskuz into branch 'release/21.12'. Fix "Select Transition" should select mixes too FIXED-IN: 21.12.0 M +8 -2 src/mainwindow.cpp M +5 -0 src/timeline2/model/trackmodel.cpp M +2 -0 src/timeline2/model/trackmodel.hpp M +39 -3 src/timeline2/view/timelinecontroller.cpp M +3 -1 src/timeline2/view/timelinecontroller.h https://invent.kde.org/multimedia/kdenlive/commit/e1cd395adb4741a8b9610e6bf91bf523bb418325