Due to a bug in the Interlaken sample channel client design, if one of the channel clients is forced to shut off, the other client will present startofpacket for two consecutive cycles.
This creates fragmented packets to the Interlaken IP core as client fails to provide the missing respective endofpacket signal to the main core.
This issue is related to the design of the example streaming clients only and not the actual Interlaken IP core itself.
This issue will be fixed in a future release of the Interlaken IP example design.