Hi,
I found the solution. Instead of using document.thisItem.isLocked(), I use document.thisItem.getAttribute("isEditState", "0") === "0".
isLocked is interesting just to know if the item is claimed or not and to know if this by you or not. It's only useful in very rare cases.
The property isEditState is interesting to know if your item is in edit mode or not. It's useful in much more cases.
This is better because now, I don't have buttons or fields enabled on item just claimed but not in edit mode.
But I have another issue that I tried to summary in this schema:
As you can see, I don't have the same state if I go through (1) or (2)+(3).
I didn't find even triggered when we go from "claimed" to "edit".
Do you know a solution on ARAS 12 ?