You could also search for the automation.turn_off service in your yaml files and see, if any match references your specific automations entity_id.

There should be entries in the history/logbook for the automation entity itself (automation.whatever). From there you should at least be able to determine, what changed the enabled state of your automation(s). If it is a service, you might have to search for specific calls of this service (e.g. in your other automations). It might also be an option to do a global text search for the entity IDs of your automations and/or any automation services. You could do this via the vscode addon if it is installed.

I myself have never encountered this error and got a few disabled automations, which haven’t changed their state over months and multiple updates/restarts.