The ePTP mode have asymmetry link

I set up the link PTP with ePTP mode. The capacity link upload/download i unbalance when upload and download at the same time. When i upload or download the link is over 100Mbps but when i upload and download at the same time i saw download is over 100Mbps and upload  is about 30Mbps via a PC to another PC (Copy file)

I ran "wireless link test" the result is Upload/download 154Mbps/139Mbps.

FW: 2.5