I recently realized that I was not getting full 1Gbit LAN speeds so I updated all the cables to internal LAN devices to cat5e and suddenly I had 1Gbit speeds between my LAN devices...hurray so far.  Then I was able to also get WAN upload and download speeds above 500Mbit/sec, my provider provides 1Gbit fiber optic.  Also find so far...and it was working great for about a week, then suddenly for some reason I do not know why, my WAN download speed dropped to 95Mbit.  Upload speed still is at 650Mbit and my computer shows it is negotating a 1000Mbit connection with the router....but the WAN is throttling all the download to 100Mbit.  I treied to bypass the C3150 and am still getting 750Mbit over my WAN connection, so something in the C3150 router is slowing down my WAN download speeds, but not upload speeds..

What could be causing this and what can I do about it?