Bee-link GT King how to switch to 1000mbps mode

hello again. my device is GT-King with CE 9.2.1 stable version installed, connected with my router via cable. and when i log in my router, i find out that the internet status is in 100mbps mode, how to switch it into 1000mbps mode?Thank you!
ps, i’m pretty sure that my router and the cable is fit for 1000mbps mode.

Do you have the latest android installed on it?