From what I understand from Daniel Baettig the problem is that you run FX valuation per year end only instead of doing this once a month. With each FX run existing valuation amounts are reversed and new amounts posted on these accounts. As you have not run FX valuation as per end of month FX gains and losses shown in your P/L as per AC1403 are not correct.
I don’t think we need a manual adjustment. Should I have misunderstood the problem please let me know and explain the problem in a more detailed way. What do you mean with ‘unlock for SAP code below’?