EOIP+IPSec Low Bandwidth Over PPPoe Connection

Hi All,

my eoip setup as below and only get very low bandwidth through tunnel.

Dedicated Internet 100Mbps → RB1100AHx2 → EOIP + IPSec → RM1100AHx2 Broadband 100Mbps-DL 50Mbps-UL .

Speedtest from other end DL around 20mbps++ and Upload get around 40Mbps++.
Anyway to improve the Download bandwidth ?
Appreciate for the help.
WhatsApp Image 2017-07-28 at 12.03.24 PM.jpeg