Hi Jonathan
This issue sometimes happens when the Incremental Data Warehouse job is running and a user goes and modifies a cost plan. If they did it when the job was running, the changes will not make it in DWH.
So I agree, try running the Full Load, this will update the records. Then if you scheduled Incremental very often during the day, I would suggest to space it out.
If you still see some data missing after that, please feel free to raise a Support case with us.
Thank you -Nika