Apple devices complain about "Weak security" on home network, but we can't change away from insecure WPA2!

For a few months now, our iPad devices have been telling us, "WPA/WPA2 (TKIP) is not considered secure.  If this is your Wi-Fi Network, configure the router to use WPA2 (AES) or WPA3 security type."  However, we are locked out of changing that setting by the system; the drop-down in our settings both through the Web, and in the app, is grayed out and we see a message instead,

Wi-Fi Mode, Security Mode, Channel Selection, Channel Mode, and Channel Bandwidth are being managed automatically to help optimize your home Wi-Fi network and improve Wi-Fi coverage. To edit your Wi-Fi Network Name & Network password, please download the Xfinity xFi app or visit xfinity.com/myxfi.

And to top it all off, when I try going to xfinity.com/myxfi, all it shows me is a screen saying:

We Encountered an Issue.

If the problem persists, check back later.

Does anyone have a way of upgrading WiFi security off of the insecure WPA2 that we're stuck with now, since apparently we're not allowed to update our Security Mode?  We seem to be forced onto a Security Mode that the industry says is NOT secure!