Somewhere deep in kdenlive's pipeline there seems to be an ugly bug which causes kdenlive to not properly apply its effects and transitions after some editing. For curiosity, a restart usually helps, but often then I still need to select another clip first, move forth and back and only then kdenlive seems to resync. And then looses soon again.
On my timeline I basically have to clips with a set of effects attached. And the upper clip is composed to the outcome of the lower clip effects.
I've basically a translate and resize effect put on a clip, followed by some color correction and finally translate, resize, and crop. The reason to do this way is that I'm using the first trans&resize effect for manual deshaking and view selection, while the final trans&resize&crop is to place the outcome into only some part of the final render view.
The second clip has basically the same set of effects.
After some editing in kdenlive I notice that I can still change the keyframe parameters of the trans&resize effects, yet the the project monitor does not reflect any changes. It plays the composed clips as if there were still the old keyframe settings in effect.
Totally strange and it makes kdenlive very troublesome to use... :(