Member formula for opening balance calculation

Summary:

Content (please ensure you mask any confidential information):

I seem to be experiencing what looks like a circular reference in a member formula for a BSO cube. I have the following accounts which make up part of a movement analysis:

• Closing Balance (Dynamic Calc) (parent)
  • Opening Balance (Dynamic Calc) (child)
    

The member formula for opening balance

IF(@ISMBR("JAN"))
  @MDSHIFT("Closing Balance",-1,"Years",,11,"Period",)
ELSE
  @PRIOR("Closing Balance")
ENDIF

The idea is to take DEC balance from prior year for JAN and the prior month closing balance for other months - very simple.

The formulas individually work e.g. if I have just the below, I correctly get an opening balance for just JAN which takes DEC prior year value :