Balance 580x WAN and LAN Bandwidth Difference

I can’t seem to figure what is going on in my Network. On the client List, a higher bandwidth utility on my WAN is shown per device but on the LAN it is far less.



For all of the WAN traffic, that is the best that can be gotten on the LAN. Are the losses? If yes, at what point is it coming from? How can it be fixed?

I will appreciate any fix or tweak.