Two things are happening:

1) In regards to Revit duct that has been brought into Fab CadMep, I can't window multiple duct fittings & go into Change Object Properties and toggle on insulation. It goes through the motions of "changes made to the item require it to be re-developed" and only some of the fittings will have insul on. There doesn't seem to be any rhyme or reason either such as, in a run of straight duct, only 2 joints will show insul, and not all types of purchased items will show insul. 

2) Carry over values isn't working properly. Carry over insulation is checked in the database and the insulation current specs are all set to "Not Set" 

Insul will carry over until I attach a purchased item, then it drops the insul.