Both ways work the same now
There are two ways to attach a reference video for Seedance 2.5: draw a connecting line, or use “+” to pick one from your canvas assets.
Until now only the first one actually ran as the task you picked. Videos added with “+” ran as general reference instead — the label was right, but what came back wasn't the kind of result you asked for. Both ways behave identically now.
The panel stops showing values that don't apply
On Video edit or Extend, the output aspect (and for edit, the length) follows the source video. So the panel now says exactly that, instead of showing a number you can change but that wouldn't take effect.
How to tell
Attach the video, pick Seedance 2.5, then choose Video edit or Extend in the prompt panel — the footer should read “follows the source”. When you see it, this run is using the task you picked.