Struggle with graph for time remapping

Hi,

I know a graph for time remapping (Fast Slow Fast) should look something like this:

But it doesn't matter how much I tried to get it done it always looks something like this:

When I try to copy the first picture it looks like this:

And thats bad...I think it has something to do with the footage, theres not enough footage?

I don't know. Between the second and third keyframe are 2 seconds footage.

Hope you can help me out 🙂