MQ topology has a MQ cluster which includes a Coord. qmgr and a Gateway qmgr, and an Agent qmgr that is not in the cluster. The agent qmgr has sdr/rcvr channels to communicate to the gateway, and a qmgr alias named after the Coord. qmgr as follows:
QR(CoordQmgr) RQMNAME(CoordQmgr) XMITQ(GatewyQmgr).
So the expected path for a transfer from the external Agent to a qmgr inside the cluster would be via the Gateway. MQ configs look correct. Receiving a RC 2087.