Dell TrueMobile router problems

[fleeteedo]

I have a Dell True Mobile 1184 Wireless router. I have been using this router and switch set up for a few years without issues. The last 2 weeks the router becomes slow and then workstations connected to the router (wired and wireless connections) slow down to a crawl. After restarting the router and cable modem all works fine for a day or so then the whole slow down process starts all over. I then have to reset everything to get everything working. I have noticed that the router will NOT issue an IP (DHCP is correctly set) address from ports 1-3. Port 4 and the wireless section issue IP correctly. I have performed factory resets through the router interface. Still the problems continue. Nothing has changed with the setup in any way, no new devices added or moved. This situation started occurring and then continued to get worse. I have to reset the router and cable modem every day now for correct operation. Any advice ?