Connectivity issue with Printer

Since I purchased this new rouder I have been having connectivity issues with Brother Printers HL3170CDW and HL5470.  My printers say they are connected to the network. I check the Netgear router by login in, and one of the printers is missing the IP address. I refresh and nothing happens.

Also, I try to add the printer to the MacBook and it does not find it.  

Sometimes it takes it and I'm only able to log in once when it disconnects.  I reboot the printers, as well as the router, and still my computer does not find the router.  I even changed the IP address.  I tried the Nighthawk app and it shows connected.   Why am I unable to add the printer to my computer?  

I purchased this router on Ebay last year and I should have tech support. I submitted a copy of my payment and I should be okay.  

Please advise how to fix this issue.