LTE7480-M804 loses connection and stays disconnected until next reboot

I am now running ABRA.7 since 2 months ago.

I now have a script that restarts the modem if pings fail, and logs the event. No restart was ever triggered so far, so maybe the issue was resolved in these versions?

Not sure why it wasn't mentioned anywhere in the changelog though.

I will update if the issue reappears.

I am actually using a smart switch on the modem to turn it off and back on if pinging google.com doesn't work.

The script is running on another router in the same LAN network, and the smart switch is connected to this second router's wifi. The cron runs the script every 5 minutes. You can turn the logging off if you don't care about that.

This is far from an ideal solution but it works so I didn't want to spend any more time on it. I'm open to improvements though!

#!/bin/sh

# Set the URL to ping
url="google.com"

# Set the maximum number of retries
max_retries=3

# Set the delay between retries (in seconds)
retry_delay=20

# Counter for failed pings
failed_pings=0

# Counter for ping retries
current_try=1

# Function to log the restart
log_restart() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') restarting" >> restart_modem.log
}

# Ping the URL and check the exit code
while true; do
    # Print the current try
    echo "Try $current_try of $max_retries"
    current_try=$((current_try+1))
    if ping -c 4 "$url" >/dev/null 2>&1; then
        # All pings were successful, so quit the script
        echo "online :)"
        exit 0
    else
        # At least one ping failed
        failed_pings=$((failed_pings+1))
        if [ "$failed_pings" -eq "$max_retries" ]; then
            # Reached maximum number of retries, so print "offline!"
            echo "offline!"
            # Turn smart plug off, wait 5 seconds and turn it on again
            wget -q --spider ENDPOINT_TO_TURN_OFF_YOUR_SMART_PLUG
            sleep 5
            wget -q --spider ENDPOINT_TO_TURN_ON_YOUR_SMART_PLUG

            # Log the restart
            log_restart

            exit 1
        else
            # Wait for the retry delay before trying again
            sleep "$retry_delay"
        fi
    fi
done

Oh my sorry for the formatting there, the post needed approval (for the code snippet I guess) and the intro text didn't look like that in the preview…

Anyway I'm going with this dirty smart switch solution because I don't have root access to the Zyxel 4G modem. I do have another router running OpenWrt so I'm able to use that script there and manage a Shelly smart switch.

It would be great if I could access the Zyxel to run scripts and manage crontab!

Do you know whether that applies to the LTE7480-M804 too?

I totally agree!
Finally had a chance to play with the Zyxel and I got root access! Thanks a lot for the guide, it definitely applies to my model too since it's the same software.

I didn't setup a script yet but I'll look into those suggested by you above.

Thank you very much 🙏