When I do multi-body work in sheet metal or welded construction, I take care to complete the personalized properties of each part that makes up the multibody (plan number, material, bending radius, ve, etc.).
When I save the bodies I also set save the properties, but when I open the room I end up with the characteristics of the multi body and not the room.
By fiddling a little, I managed to get around the problem.
And I think I know why Solidworks is creating this little bug.
Let me explain:
When I saved the bodies of your multibody, Solidworks has saved the bodies in "Stock".
The only way I found was to convert this part to sheet metal afterwardsto recover all the associated properties.
But I don't understand why Solidworks doesn't register your sheet metal bodies directly.
So I looked at your design. I noticed that you use a lot of sheet metal conversion. So I guess this accumulation of sheet metal conversions is bugging Soldiworks at this level.
Conclusion: Favor the design directly with the sheet metal module, instead of going through a boss or other.
Try redoing your part with only multibody sheet metal and try to register the bodies again.
I'm going to modify my design to see if I can find the properties
Then I register the bodies because I use the parts for other customers who have the same filters but with different dimensions depending on what they have to filter, cement, dust, fumes, etc
thank you again, I'm doing a test to see if it works
In any case, even by converting the so-called "stock" part I don't get the same result as you, I'm really bad