Hello, dear.
Please tell me your product model.

Based on the image you provided, we can currently know that the red box below is the estimated value given by the system based on the link quality. The higher the estimated value is related to the modulation mode you choose in the red box above, the higher the modulation mode, the easier it is to reach 700Mbps.
You can select the first red square to see if there is an option in the drop down menu that can reach 700M, if there is no option above 700M, you need to provide your operating mode. is8 or is6?