Program starts from rc.local but doesn't do anything

I have a program which uses msqllib. It scans some hardware that I build and then updates a mysql database. This program has been running for a number of years but I have never been able to autostart it when the system reboots. Now I have an issue with power cycling that is beyond my control, so want to get it running automaticaly. In rc.local : I have: #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. # Print the IP address _IP=$(hostname -I) || true if [ "$_IP" ]; then printf "My IP address is %s\n" "$_IP" fi /home/nigel/scan exit 0 Now, the code runs fine when I enter it at a command prompt, and updates my database. However, when I put it in rc.local, ps -ef shows: root 356 350 0 20:54 ? 00:00:03 /home/nigel/scan but the program is not executing the SQL calls to update the database. If I ask for the statius of rc.local: root@Pi-Scan:~# systemctl status rc-local.service ● rc-local.service - /etc/rc.local Compatibility Loaded: loaded (/lib/systemd/system/rc-local.service; enabled-runtime; vendor preset: enabled) Drop-In: /usr/lib/systemd/system/rc-local.service.d └─debian.conf /etc/systemd/system/rc-local.service.d └─ttyoutput.conf Active: activating (start) since Sat 2023-05-06 20:54:19 EDT; 12min ago Docs: man:systemd-rc-local-generator(8) Cntrl PID: 350 (rc.local) Tasks: 2 (limit: 414) CPU: 3.903s CGroup: /system.slice/rc-local.service ├─350 /bin/sh -e /etc/rc.local start └─356 /home/nigel/scan May 06 20:54:21 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:22 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:23 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:24 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:25 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:26 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:27 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected May 06 20:54:28 Pi-Scan rc.local: error: first parameter is not a valid address family: Transport endpoint is not connected However if I issue systemctl restart rc-local.service The program executes a second instance and works fine! Thinking that this may be a racing condition, I have tried adding a sleep 5 before the command and still get the same problems.