I had this same problem with our hangers. There were a couple of things that we were doing wrong here.
1. Turns out the material specification may drive the function of the hangers. This is not always true, but supposedly over-rides the sizing based on material. If a hanger specification is set to "General Pipework" and the Material "Carbon Steel, STD" or "Carbon Steel, A53" The hangers will only recognize that specification for sizing. In that case, it would be correct for an Anvil Fig 260 Adjustable Clevis Hanger, but not a copper teardrop.
2. If you have any periods in the name of the itm, this will cause errors in the functionality of the hanger. Autodesk said they were going to fix this, but who knows. I reported the issue in December, and haven't seen any notes on it. I had to remove all the periods from the abbreviation Fig. as to fix that problem.
3. Hanger vs. pipe size - In the product listing, if the pipe and hanger use different size indicators. For example, size of pipe is .125, .25, .375, ect and the hanger is .125", .25", .375", ect. The " after the size can cause it to not place the correct hanger.
4. Product List Name - I proved to Autodesk that the name can affect it also, even though they didn't believe me at first. I created the same hanger with different names, but used the same Product list and support settings. Then changed the product list names to use dashes in fractional format. 1-1/4" vs. 1 1/4. They created different sized hangers on the same piece of pipe. Autodesk said they are also looking into this.
