I have that same problem. They told me to try and use a tab instead of a return after entering the new elevation value. I have yet to check that solution. The drawing I'm working in right now, allows me to use the return or a click of the mouse. So their recommended Tab button really correcting the issue, is still up in the air with me. Let me know if that fixes it for you. Otherwise there is still something going on that Autodesk needs to fix.