Hey try looking at the splitter that the modem cable is connected to, also inspect the cable line(s) to see how they look. Turn the modem off before you do this though, check the connections at the splitter, if they look anything other than clean then you may have a problem. Signs of contamination would include a white or black power, green residue, water in the connection. If its clean you can try replacing the splitter with another one, it should be rated at 3000mhz. Also where I have seen issues with signal at is where the modem is hooked up at in the overal system. The modem feed line should only have one splitter between it and the drop from the pole to the house, you should also consider inspecting the wall plate if there is one to see if the barrel connection is even rated, if its clear then you have a barrel connection thats not rated for 3000mhz.