I had not worked in v0 for a while, and when I came back I ran into exactly the same issue. I actually just created a new post about it here:
This new experience feels quite cumbersome. What makes it more confusing is that, when Design Mode was introduced, it was presented as a way to make quick UI changes without editing code or spending credits:
That functionality does not seem to have lasted very long. Now even a minor manual change has to be sent through the chat and can consume credits.
Have you found out anything else about this? Do you know whether this was an intentional change related to costs, or whether there is still a way to use the previous workflow or switch back to it?