Just a note as I answered this in another thread.. so to add to the two amigos.
From other sources I have seen iOS 14 will show weak security with WPA2 TKIP which requires upgrade to AES.
https://www.howtogeek.com/204697/wi-fi-security-should-you-use-wpa2-aes-wpa2-tkip-or-both/
Apple has never actually shown any difference between TKIP (older security for WPA) and AES (current standard) which some routers do.. it has always just shown personal. (PSK is also common term.. Personal Security Key which apple shortened to Personal)
IMPORTANT. Make sure you have WPA2 Personal checked in airport router.. NOT WPA/WPA2 Personal which will allow TKIP and/or AES.
Let me double up that warning.. as your eye might skip.
***The most important thing is to NOT use the option WPA/WPA2 Personal which will be TKIP + AES***
Compare that to a more modern router
There are a number of options for Authentication Method same as Apple uses.
But none for Encryption. You should be forced to use AES with WPA2 which is as it should be.
However if you set WPA then you can have both TKIP + AES meaning security is compromised when using that option. At least the Asus router allows you to force AES on WPA and not the usual combined TKIP + AES
One thing to check if you have multiple Airport routers is that all are set to WPA2 Personal. None should have WPA/WPA2. And if you have a modem router with wireless ensure it or any other wifi Access Point, Repeater, Mesh etc is also set properly.
