You encounter unpredictable behavior when attempting to remove entities from a maintenance window in the DX Operational Observability GUI. This issue specifically occurs when you add subsequent entities to an existing maintenance window and then try to remove some of them. While the initial removal appears successful, the system does not consistently update or remove the correct server.
This behavior is related to product defect (DE675955) related to how the Graphical User Interface handles updates to existing maintenance schedules when multiple entities are involved.
Fixed in upcoming 26.1 hotfix 2. For an update contact Broadcom Support