Wi-Fi connection(to wireless LAN AP) is lost immediately after 11 hours past with WPA3-SAE. We think it was caused due to Wi-Fi module is down. It's not disconnected by wireless AP. And we have already tried other wireless LAN AP from several vendors, and we confirmed that the same issue was reproduced in every case. However, if we choose WPA2-PSK, the issue doesn't happen. Wi-Fi connection is still alive after 11 hours past.
We think the Wi-Fi module doesn't go into standby mode. Because the Wi-Fi module still communicates with servers.
The Wi-Fi module is communicating with a specific server on the internet, the Wi-Fi module is sending a keep-alive packet to the server every 5 seconds. We have captured regular packets between the Wi-Fi module and the server on the WAN side of the wireless LAN AP. After 11 hours, we can no longer find any packets transmitted from the Wi-Fi module. Adding to this, we find a record that shows disconnected from the Wi-Fi module on the wireless LAN AP's logs roughly after a few mins from when we missed any packets incoming from the Wi-Fi module.
This is a captured screen that shows communication packets captured by the packet analyzer when it's disconnected from Wi-Fi. The least 1-Byte hex number "1e" in MAC address is the Wi-Fi module, "30" is wireless LAN AP. Since we started to capture some time after connection, these timestamps in captured data don't match to actual time.
We confirm that the Wi-Fi module sent "Deauthentication" management frame when the Wi-Fi module was disconnected. At the same timing, we confirm followed logs on console of the Wi-Fi module, too.