Keyframe Stretcher doesn't work properly or what should I do

So, I made new Fusion composition (100 frames) and open it on Fusion page. Make some animation with Transform node (from 0 to 15 frames and from 85 to 100 frames). And set Keyframe Stretcher like this: Soirce Start — 0
Source End — 100
Stretch Start — 15
Stretch End — 84
After that I put Fusion composition on timeline.
If I try change duration in smaller direction — I have black frames from about 80% of Composition
If I try change duration in other direction — sometimes I have first frame like without any settings and nodes and from second frame I have ani,ation
What should I do to avoid this? Thank you!
P.S. I have several strange behavior (or bug) more. Need I make new topik about each one?

HP Z820
2xIntel Xeon X5-2687w
64 Gb RAM
1 Gb SSD ROM (about 3500 mbit/sec)
RTX 3060
Win 11
DVR Studio 17.3.2 build 8

Keyframe stretcher is for keyframes not the duration of the media.
Am I misunderstanding?

Keyframe stretcher is for keyframes not the duration of the media.
Am I misunderstanding?

I don't know, manual say use it for change duration. Or not only I misunderstanding it.

Had the same issue. It seems that the problem was that the number of "source end" in the keyframe stretcher node was bigger than the actual number of the frames in the clip.

In my case - I made a 3 sec clip which is 75 frames @ 25fps. I think the Keyframe stretcher's default source end is 120. When I changed it to 75 it started to work properly.

Keyframe stretcher only moves keyframes. To alter the clip duration will require changing the speed of the clip itself.

Keyframe stretcher only moves keyframes. To alter the clip duration will require changing the speed of the clip itself.

I think you misunderstood the question/problem. You can change the length of a fusion clip in the timeline by dragging the start or end of the clip. Keyframe stretcher is there to move the keyframes along with both ends so that animations would still work if you drag the clip shorter or longer. I don't think they tried to change the length of the clip with the keyframe stretcher.

As far as I understand (and I had the same problem myself) the issue was that when the clip's duration was dragged shorter in the timeline, the animations stopped working properly and about 20% of the ending of the clip turned black.

In my case at least the problem was that the "source end" was accidentally a wrong number. Bigger than the clip's length.

Keyframe stretcher only moves keyframes. To alter the clip duration will require changing the speed of the clip itself.

I think you misunderstood the question/problem. You can change the length of a fusion clip in the timeline by dragging the start or end of the clip. Keyframe stretcher is there to move the keyframes along with both ends so that animations would still work if you drag the clip shorter or longer. I don't think they tried to change the length of the clip with the keyframe stretcher.

As far as I understand (and I had the same problem myself) the issue was that when the clip's duration was dragged shorter in the timeline, the animations stopped working properly and about 20% of the ending of the clip turned black.

In my case at least the problem was that the "source end" was accidentally a wrong number. Bigger than the clip's length.

In my case seems too. Source End has a wrong number