Since you said “agents” I presume this is a call center? If yes and you’re using UCCX, check out Configure an Auto Answer with Finesse. It has the advantage of only answering ACD calls vs. risking a hot mic for direct calls while the agent is Not Ready or logged out. UCCE/PCCE has a feature for this as well, although I believe it’s implemented differently.
I would have bet that the Jabber CSF device type supports CUCM auto-answer though; I’m surprised to hear that isn’t working.