bandwidth test

hello

I have CRS109 V 6.32.3 . The wan PORT is connected to fiber ONT . I have a problem with bandwidth on WAN port .
bandwidth ONT = 400 Mb/s
bandwidth ether2-master-local = 100 Mb

ether2-master-local : Bandwidth (Rx/Tx) = Umilited .
MTU : 1500
Auto Negotiation done
Rate 1Gbps
Full Duplex
1000M full
Link Partner Advertising
1000M full

I don’t kwon !!!

Thank you for your help …

Regard