Well, it is still better than manually modifying the agent. Also, you always want to keep your agent and server version aligned.
But after reading this post one more time I get the following hunch:
Something is causing a systemctl process to become a zombie. There are very little calls to systemctl in the agent, so it might be some external factor, that is causing the systemctl process to misbehave, so the agent script cannot pick up the return of that. Maybe you investigate into that direction, to see what might be interfering with systemctl.