A UE receives DCI in a PDCCH, the DCI triggers reception of AP CSI-RS, and the PDCCH has a first numerology and the AP CSI-RS has a second numerology. The UE determines, when a CORESET is configured on an active BWP of a serving cell for receiving the AP CSI-RS and when the first numerology is the same as the second numerology, a default AP CSI-RS beam for receiving the AP CSI-RS based on a beam used for receiving the CORESET with a lowest ID in a latest monitored slot of the active BWP of the serving cell. The UE determines, otherwise when the first numerology is the same as the second numerology, the default AP CSI-RS beam for receiving the AP CSI-RS based on a QCL assumption of a PDSCH TCI state with a lowest ID on the active BWP of the serving cell for receiving the AP CSI-RS.