Lock: don't lock automatically tasks that I unlocked

What I'm trying to achieve is that tasks that are in the list (left-side) that are dragged onto the calendar are automatically locked. I enabled this setting to achieve this.

However when I manually unlock certain tasks once they're already in the calendar, and then try to drag them to adjust their time, they are automatically re-locked.

I expected the above settings switch to only apply to tasks that have not been planned with a specific time in the calendar yet.