Cant make Roblox animation editor animation time length smaller than 2:12

[3DesignD]

I have a animation I imported from a video of myself, however, when I try to make it smaller than 2:12, even if there are lest animation key frames, this happens

It will not get any smaller than 2:12, just in case there was a animation key frame lingering somewhere as for the reason to why the animation time did not get any smaller, disproved after I made the canvas size huge and saw nothing.

This is how I made my animation: First I imported it from a video of myself, then I only kept the right arm animations. The last step was to make it a perfect loop, but I could not resize it to the last animation keyframe as it stops at 2:12. How do I fix this, any suggestions?

[3DesignD]

it seems that time barrier thing only shows up when i play the animation for some reason, so i just have to make the animation, then play it, and once i play it the time barrier will be there and i wont be able to change time length no more

I just now made the animation again without playing the animation once, fixed it.