Not able to connect to internet using Linksys EA7300 and Bitdefender BOx

Up until yesterday this was my setup: gigabit internet coming in from the wall jack (no modem) going into my Bitdefender Box, my Linksys EA7300 plugged directly into my Bitdefender Box and my devices connected to the wireless network from my router, not the Bitdefender Box wifi. It had worked great for about a year and yesterday it stopped working. I reset both my router and my Bitdefender Box to the factory settings. If I plug the Bitdefender Box directly into the wall jack and directly connect my laptop via an ethernet cable to the Bitdefender Box I can browse the internet. Likewise, if I plug my router directly into the wall jack and connect my laptop to the wifi from my router I can access the internet. But when I have my Bitdefender Box plugged into the wall jack, my router connected to my Bitdefender Box with an ethernet cable and my laptop connected to my router's wifi I am not able to access the internet. There is nothing wrong with my router because using just it I am able to connect to the internet. There is nothing wrong with my Bitdefender Box because using just it I am able to access the internet. The problem is when I try to use them together I can't access the internet. I know this can be done because I used this exact same setup for over a year with no problem. I'm willing to bet that there is just some setting either on my router or my Bitdefender Box that needs to be tweaked so I can get them to work together like I have before. I don't want to have my router operate in bridge mode because I want to manage my devices with my router, not with the Bitdefender Box. Please help me! Thanks in advance.