OK. With respect to the error in the logs, I suspect but will have to confirm that the error is because device 27 is sending an event for a non-existent device in Hubitat. That should be harmless, and shouldn't throw an error. So I will investigate making the error go away. Also, that would have nothing to do with your issue with the other VCRX, device 28.
So I don't see anything wrong with this on the Hubitat side. It is sending the push command to CCO1 as it should, as evidenced by the response from Lutron (rcvd: DEVICE,28,1,3).
You could test this without Hubitat in the loop at all by opening a Telnet session to the main repeater. Give it the command #device,28,1,3. You should get back that message from Lutron, and that pushes that output button and the corresponding button on the VCRX.
Did you set the CCO output to a pulse duration in the Program section of the Essentials software?