I don't know why. But it works well as expected in my place. Posts and videos, all can be downloaded.

Update in 7/8/2023: It seems to be my fault. I only test the new-tab button but no download button. I have uploaded a new version 1.2.7. I hope it works for you.

I tried in the homepage,it still works. Do you give the add-on permission manually?(https://user-images.githubusercontent.com/22173084/241606818-f6988f38-46fc-4c9c-a37e-35a25e71dbe4.png)