My AX21 (AX1800) offers a choice of WPA3 Personal + WPA2 AES among the protocols in the drop down menu for wifi encryption, and that option works for the legacy devices on my network that only...

Using a Wifi Analyzer app that shows details of the wireless networks in my vicinity, I see that the RE600X extender's hidden network is using a Beacon Interval of 100ms (0.1024 seconds). I have my...