Hello,
from the problem description this looks like an issue related to pricing on item level. In standard the following condition types are used:
KAPPL KVEWE KSCHL
CRM PR 26C1 Claimed Amount (CP)
CRM PR 26C2 Claimed Amount (BO)
CRM PR 26C6 Rejected Amount
CRM PR 26C7 Authorized Amount
Can you check the same in your scenario. Are you using the standard claim item categories or your own ones? What is the pricing procedure used?
best regards,
Johannes