Can't Change Opacity on Clip

Describe the bug
I cannot permanently change the opacity of a clip which I have put motion tweens on. When I change frames, it goes back to what it was.

To Reproduce
Steps to reproduce the bug, if you have them:

  1. Select any frame of layer “Chair FRONT”
  2. Select the clip in that layer, and set it’s opacity to something new.
  3. Change frames.

Expected behavior
I should be able to alter the clip’s opacity.

Screenshots

*Computer Information

  • OS: Windows 10
  • Browser
  • Firefox

The .wick file: https://drive.google.com/file/d/1vYlWn3rSY-h19MoTO-Ct1GRTSUWoiSrh/view?usp=sharing