I have an existing booking for three. Outbound is BOS-DXB-PEK in EK J, inbound is originally MUC-BOS in LH J. I would like to add a segment from China to MUC. I identified a TK J HKG-IST-MUC segment a few days before the MUC-BOS segment and called in to add it. However, the Aeroplan agent was unable to add the segment, saying the system returned "HL" rather than "HK" when executing it.

I wonder if what could be the cause for the failure? It appears I was not against Aeroplan's booking rule with both bound to be Asia to North America and the stopover in Europe should be allowed? I HUCA'd but the second agent also could not do it.