In v18, when I use a keyframeable effect, I can use the timeline cursor and then add the key frame.
In v19.12, the cursor in the effect property doesn't move along with the timeline cursor (bug?). So I have to use the tiny slider in the property. That's very hard for fine tuning.
Any advice?

this was fixed 2 months ago'... https://invent.kde.org/kde/kdenlive/issues/127
just downloaded latest nightly and i tried to move the "transform effect" cursor using pointer on timeline and it's working as expected.

do you have this issue only on a specific effect?