Mechanically welded nomenclature 2019

Hi all

I just upgraded to SW2019 SP1.0. I use the mechanically welded function a lot. Usually I create an automatic bill of materials in "tabbed list" with "flat numbering" and "detailed list of welded parts". In the nomenclature I selected the lines and used the "decompose" function.

Since the change of version I have had problems. Indeed, if I "decompose" the lines are deleted or the nomenclature corresponds to our way and as soon as I make an update the nomenclature "recomposes " and adds all the lines that I had decomposed.

Of course, I have disabled the automatic update function in the mechanically welded function of each of the parts.

Does anyone have an explanation for my problem and especially how to fix it?

Thank you in advance