In 4.14, changes were introduced to share replicated state between objects on the server (Shadow State) this was done to allow sharing property comparisons to determine when objects needed to replicate to clients.
On the server, the shared replicated state is stored in FRepChangelistState::StaticBuffer. For clients, or when receiving properties, the state is stored in FRepState::StaticBuffer.
FObjectReplicator::ValidateAgainstState was never updated to reflect that, so on the server we still use the FRepState version, which always reports errors.
No warnings are logged
Warnings like "FDiffPropertiesImpl: Property different: <PropertyType> <PathToProperty> always complain about being different when the actor becomes dormant and when it becomes no longer dormant.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-65603 in the post.