Are you adding pipes to your BIM model using REVIT MEP? If you run into a problem getting your insulation to appear correctly, try reconnecting your pipes at the offending fitting by first breaking the connection to the fitting and then reconnecting it using the grips provided.
The RCP pipe shown above has a 5" Insulation on the elbow to match the pipe it is connected to simulating the 5" thick wall of the concrete pipe. Problem is, the fitting doesn't display correctly even though the system is connected...And the setting is saved in the element properties as shown below.
The Fix...Break and reconnect it using grips.
This will reset the insulation to 0". A quick trip into the element properties, resolves the problem by adding the 5" setting again!
Note: "Delete and undo did not work!"