@JoãoASilva , there was a change in Inventor 2021. To fix a problem (internal number INVGEN-34263), we changed it so that if any member dimension shows Attached = False then they all do.
If you happen to delete all the members that are truly detached, then the set as a whole will be attached. At that time, the remaining members will show up as attached.
This makes it very hard to find the members that are truly detached. It looks like we should restore the behavior of Inventor 2020 and earlier.
For now, you can work around the problem with the attached rule. This is based on @dutt.thakar's rule. Instead of looking at the Attached property, it looks at other properties of the dimension to see if it's valid or not. In some cases it needs to know the positions of detached centermarks.
This rule might need to be generalized to handle other cases.
Mike Deck
Software Developer
Autodesk, Inc.