Unable to inset on ends, but sides OK

 From:  MO (MO_TE)
12098.4 In reply to 12098.1 
Hi James,
I'm not sure about the reason of this, but I tried "ShrinkTrimmedSrf" command on your object and that fixed it.
Select your object, press TAB, paste "ShrinkTrimmedSrf" and press Enter.