Note: Since I've offended the WiFi 6 lovers - This solution disables WiFi 6 (AX) capabilities (which you probably don't need) but gets you back up and running, until a) You decide to return your router and get something other posters below recommend and hope it works for you

or

b) You decide you don't care about WiFi 6 rn and can figure it out when you do, and just need to get back up and running

Since after doing a fair bit of research including contacting Apple and Netgear, I couldn't find this answer in clear and direct words, posting this to help someone who is about to throw their wifi router out the window.

My 2019 Macbook Pro and older iPad would keep dropping / freezing up the WiFi connection to my new Netgear Nighthawk RAX-120v2 WiFi 6 enabled router. Some say it's an issue with Apple (and other) devices wifi chips, others say it's a Netgear issue - I haven't come across a clear enough answer, and I didn't have more time to research/debug.

These routers are expected to be backward compatible but as it turns out, may or may not be out of the box. I tried everything - Flashing the older router firmware, with and without SmartConnect for auto-band detection, renewing my Mac DHCP licenses and changing packet sizes, none of it worked.

A working solution (until you upgrade to newer devices with a newer $*@&!^g WiFi chip or Netgear/Apple decide to get their ish together), is to uncheck/disable "Enable AX" in Wireless settings. Re-enable it to take full advantage of WiFi 6 again in the future, when you can. While you may not be taking full advantage of WiFi 6 today by doing this (read: you probably don't need to) the good news is your router is future proof and may not need to return it.

Cheers, and happy long weekend all!