I changed from hostapd to NetworkManager, as I upgraded to the Debian Bookworm (more recent Raspberry OS). As now the NetworkManager manages everything, an it is quite convenient, I set up the Wifi AP using NetworkManager:

    sudo nmcli con modify My_AP wifi.band bg
    sudo nmcli con modify My_AP wifi.channel 3
    sudo nmcli con modify My_AP wifi-sec.key-mgmt wpa-psk
    sudo nmcli con modify My_AP wifi-sec.proto rsn
    sudo nmcli con modify My_AP wifi-sec.group ccmp
    sudo nmcli con modify My_AP wifi-sec.pairwise ccmp
    sudo nmcli con modify My_AP wifi-sec.psk "mypassword"
    sudo nmcli con modify My_AP ipv4.method shared ipv4.address 192.168.5.1/24
    sudo nmcli con modify My_AP ipv6.method disabled
    sudo nmcli con up My_AP

Now I need to configure the ap_max_inactivity setting, as it was possible with hostapd. If a device disconnects because of a sudden power loss or reset or similar, it will not properly disconnect. Therefore, I would like to check every ~10 seconds, if the connected devices are online, as the ap_max_inactivity (send empty data frame and check for ‘Ack’) does. If there is no ‘Ack’, the connection should be removed, so that the device can reconnect. Currently, the device cannot reconnect to the AP, until a deadtime of approixmately 3 mins is reached. Is there a possibility, to shorten these 3 mins to 10 seconds? If so, how and were is this configured? Thanks in advance, cheers

I already searched the docs of NetworkManager, it does not seem like there is such an option.