One full re-install later.
Port 80 doesn’t work so this is what I did.
pm2 delete server
Then did
pm2 list
to make sure server wasn’t running
Then as per your suggestion did
PORT=3000 pm2 start server.js
Then this is the important bit or else when you reboot it goes back to port 80, you need to do
pm2 save
A quick read of the pm2 docs pointed me to this. I noticed the startup file used the command pm2 resurrect . Which brings back previously saved processes (via pm2 save).
Rebooted and it all works on port 3000
So once again many thanks and got there in the end.
The website for pm2 docs is https://pm2.keymetrics.io/docs/usage/quick-start/