A recent firmware update (18.1.c.512-950-RB or 0.12.09r) enhanced the modem's WiFi security with the addition of Protected Management Frames (PMF). Protected Management Frames is a standard defined by WiFi Alliance to enhance WiFi connection safety. It provides unicast and multicast management actions and frames a secure method with WPA2/WPA3, which can improve packet privacy protection. It causes problems with some devices manly old devices that only support the 2.4 GHz WiFi band. Some older WiFi devices especially those that only support the 2.4 GHz might experience problems.
If one or more of your WiFi devices experience any off the following problems the problem might be due to PMF being enabled in modem.
Device want connect to modem’s WiFi common error is wrong password.
Devices connect but don’t have a valid IPv4 address.
Windows devices crash with blue screen of death.
Devices reboot when WiFi on modem is turned off and then back on.
Devices connect okay but loose connection intermittently.
Turn of Protected Management Frames in the modem's WiFi settings.
If you have the Technicolor modem (DJA0231 or DJA0230) log into modem (http://192.168.0.1, password is Telstra), go to Advanced > WiFi, scroll down to Protected Management Frames, set to disabled and save settings. If the problem occurs with 5 GHz devices repeat for the 5 GHz WiFi network.
If you have the Arcadyan modem log into modem (http://192.168.0.1, password is Telstra), go to WiFi, scroll down to WiFi-PMF, set to off and save settings. If the problem occurs with 5 GHz devices repeat for the 5 GHz WiFi network.