When you switched ports, did the same ports work or did the same devices work? If the same devices work, then try new ethernet cables for the failing devices. If it is the same ports on the router...

Many devices only operate on the 2.4 Ghz and not the 5Ghz. You need to check each device's specs.

What is your setup and how are you using the netgear router. What was your working setup prior to the A10?

I would try powering all down al devices including modem and router and then back up one at a time and if that did not work then I would reset the router to factory settings and re-enter all of the...

Check your guest network and see if you can control the WIFI times for it. If so, use it instead.

Router selection depends on a lot of things. What is the speed from your ISP? How many and what type of devices are going to be connected to the router? How large is the coverage needed? Any special...