Why do Historical Override Accounts not balance at base Movement members?

Summary:

We noticed this year that whenever there is activity in an account deemed as Historical Amount Override, the way in which FCCS consolidates and translates that data causes it to not balance at the FCCS_Mvmts_FX_Movement and the FCCS_Mvmts_Subtotal (these two offset each other). I believe the issue is due to how the activity members are derived systemically and the override amount throws off that calculation. On the attached file you can see our Assets - Liabilities - Equity check in row 31 and the subsequent variance. To the side I've calculated what I believe should be