Hi @Greebo, found the problem - service-runner is looking for service-runner in Redis, when in fact I have emoncms:service-runner. I think this was the recent change to the Redis options in settings.php.
I鈥檒l open an Issue. Redis prefix in service-runner 路 Issue #1167 路 emoncms/emoncms 路 GitHub
[edit] Also explains why the command redis-cli lpop service-runner returned nill. When I changed the python script, it started creating a whole load of backups 