This has happened in the companies I manage.
The OCS Agent services simply disappear.
In this case, I created a BAT/CMD script that validates the existence of the service; if it doesn't exist, it creates it pointing to the file in its correct directory.
If the file doesn't exist, it reinstalls the OCS Agent.
If everything is OK, it simply forces an inventory, which doesn't cause any harm.
If you are interested, contact me via WhatsApp +55 62 9 9410-8188