This is an existing regression issue occurring for Content Manager and Member Portal systematic interactions. When interaction is first created, you can see in Audit history that it first assigns to broken processes due to an error that D_Interaction is missing InteractionID, however it immediately reprocesses correctly and assigns to the expected WB. However, because this initial broken process is happening, when you process these interactions in certain ways, it is changing the Assigned Operator to Broken processes in the Review Harness.
This needs to be fixed. Refer to NB-4829 for details.