Hi,
From your analysis, I understood it might be the revaluation entry that is missing the actual cost component split. I wonder if the actual price calculation (KSII) updated the cost component split correctly, that may resulted missing actual cost component in the revaluation entry. You can check if there is any warning or error messages at the time of price calculation or revaluation.
You can try to check if there is any inconsistency in actual cost component split through CKMHELP t-code. That may give some clue.
You can refer the below two OSS notes.
https://launchpad.support.sap.com/#/notes/1939798/E
https://launchpad.support.sap.com/#/notes/2213992/E
Hope this may help you to dig further to understand the root cause.
Thank you,
Srinath