Hi louis-philippe redaud Thanks for your patience! As discussed, this behavior is due to Canvas option if its ON then you won't see actions being expanded. But if off then action boxes get expanded.
as you need the old design with action box not expanded, product group team informed that they will look into it but the investigation will only happen at a much later ETA due to other priorities and because this issue seems to only be affecting a couple individuals, it cannot be prioritized immediately.
similar threads for reference: https://learn.microsoft.com/en-us/answers/questions/728364/logic-apps-consumption-new-canvas-mode
Let me know if you have any further questions.
Please "upvote/accept" if the answer is helpful so that it can help others in the community.