Well, to nobody's surprise, Netgear STILL has NOT done anything to resolve the firmware compatibility issue between the RAX40 and EAX20 (though I'm fairly confident that other EAX extenders are also impacted).
If you haven't already found it, the newer versions of the RAX40 firmware do not allow proper connectivity with the EAX20. However, someone was able to identify what version of the RAX40 firmware is the last compatible with the EAX20.
Unfortunately, you need to downgrade the firmware on the RAX40, and you lose some of the newer security capabilities.
Anyway...
You downgrade the firmware on the RAX40 to v1.0.3.64
This is done no differently than updating the firmware. Download the firmware from Netgear and unzip the files, connect to the RAX40, go to the page to update the firmware, browse for the file. Again, the rest is no different than updating firmware.
I did this and things worked like a charm. I'm more than a little annoyed that I lost WPA3, but at least I got the two devices linked up.
Here we are, two years later... and NETGEAR has STILL NOT resolved the compatibility issues between these two devices. Coming here, relieved me a little seeing that this was a much wider problem... I was a bit p!$$ed because I had a EAX80 that I returned because I thought it was defective and purchased the EAX20 instead. What ticked me off all the more was that support was CLUELESS about this KNOWN defect in the product.
I'm glad that others posted the solution about downgrading the firmware on the RAX40, but that also had some agitation with it because I lost the newer security features like WPA3. This is particularly of concern given the current environment of the Internet being filled with bad actors trying to steal your information or identity.
As good and reliable as NETGEAR equipment has been for me over the past decade plus... to say I'm very disappointed is a gross understatement. I might keel over dead if they actually FIX this @#$&%$*@& problem.
I remember seeing your post awhile back, I had the same issue with firmware compatibility for the past couple years. Super frustrating.
Just wanted to let you know that I tried updating my RAX40 router firmware version to 1.0.6.106 last weekend and my system is currently holding stable (knock on wood!) with no compatibility issues with either of my EAX20 and EAX18 extenders.
In case you have issues and need to downgrade again, I recommend having the previous firmware that was working (1.0.3.94) already downloaded (don't want to get stuck).
