Brother printer keeps dropping from network

As I dig deeper I am getting more and more confused. Using Network Diagnostics both Macbooks come back saying

However, the router was restarted, and when I open network preferences it says I am connected to Wifi network and shows me the IP address, and I have full internet connectivity. When I run a diagnostic scan it shows no outside networks, but does show my 3 networks - 5 ghz, 2.4 ghz and a guest network, but it shows duplicates of each of those - perhaps from my access point?

Yes, the router has been rebooted several times during this process. The printer was reset to factory defaults on some of the times I was troubleshooting it. It has the same behavior whether I rest to factory or just reset the network settings. I'm reading up on how to see if any neighboring WiFi networks are using the same channel. I did note on one time yesterday when I woke the printer and printed a network configuration report it was using an IP address via APIPA which I had not seen before. After I reset network settings it went back to using a DHCP address. I'm also noticing that my IP address falls within the range of IP addresses per the network configuration report. However, since this is an intermittent problem I'm not sure any of these anomalies are responsible for the problem.

I also tried pinging my printer from my Macbook Pro and it is successful, but the same ping from another Macbook Pro in the home is unsuccessful. Neither Macbook finds the printer if I go into Printer settings and try to add a printer to the network.

As far as I could tell none of the devices were actually connecting through the AP - AP was a bit of a misnomer as the device was configured as a network extender to boost signal strength in parts of the house.

Later I will test out removing the extender. For argument's sake let's say that does turn out to be the issue. What would be the best route to go to extend coverage because our wi-fi in other parts of the house was pretty poor before I added the extender in. Running wires in the house was not really an option - it could be done but it would be tricky.

I took the extender out and it made no difference. The printer connection comes and goes. Sometimes I print and it says printer not connected, and 15-30 minutes later it prints the document. Other times the printer doesn't even show up for family members to choose it, and then if I reset the printer wif-fi by re-entering the network password it will show up on the network for a while, and then disappear again. Since Brother and Verizon and Apple all seem to have no answer and I can't even pinpoint who should have an answer on this it may just be more efficient to buy another printer.

So I finally had another few minutes to try to troubleshoot this, since for the past couple of months our printing has really been a problem. This time I took out the extender again and the printer responded right away. So for now I am going to assume the extender is the main culprit in the printing issue. However, this leaves me once again looking for a way to extend the range of the wifi signal wirelessly since running hard wired connections through the walls is not really an option for me. Are there other access points/extenders that will work better than what I had which was an Actiontek WCB3000N configured as a network extender.

If I were to try this, and I add an IP outside the DCHP range, I assume I then need to somehow enter this address into the printer. Which setting am I supposed to use to enter this? I can navigate to the TCP/IP settings screen but can't seem to make any changes.

https://support.brother.com/g/b/faqend.aspx?c=us&lang=en&prod=hl1450_all&faqid=faq00000347_002