The animation sequencer works very strange at times. I have an animation that needs to be cut into several separate animations. Sometimes it cuts as it should, and sometimes when I try to remove extra frames nothing happens, the timeline just returns to the zero frame, the extra frames are not deleted. Moreover, when the engine is restarted, the same actions work. Sometimes it is not possible to select the desired range of frames at all, as in the picture. Am I doing something wrong and using this tool incorrectly?