Commercial Fixed Wing
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 15
Physiological - Other; Fatigue; Distraction; Communication Breakdown; Situational Awareness; Workload
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Company Policy; Staffing; Environment - Non Weather Related; Human Factors; Procedure
Aircraft X was level at 11;000 ft. westbound. I took a handoff from TRACON of Aircraft Y out of 9;500 ft. climbing to 11;000 ft. obviously merging with Aircraft X but didn't realize it until too late. I first called TRACON to see if they were working Aircraft Y and if they were to stop their climb at 10;000 ft. They advised they weren't working Aircraft Y. I then called a different TRACON sector and told them to stop Aircraft Y at 10;000 ft; but they told me they switched the aircraft to another Center sector even though the aircraft would never enter their airspace. I called that sector and told them to descend Aircraft Y TO 10;000 ft. AND TURN 30 DEGREES RIGHT. They called me back and said they weren't talking to Aircraft Y. I then noticed Aircraft Y descending to 10;000 ft. and they checked on my frequency. At this point; I had separation between the 2 aircraft but then TRACON descended Aircraft X to 10;000 ft. thus losing separation as they were about 1 mile apart. I turned Aircraft Y 30 degrees right to avoid collision. They passed directly behind Aircraft X. I believe this is an event that happened because of the major added stress because of the government shutdown. My mind clearly wasn't working as fast as it needed to. There should never be an aircraft aloud northbound on V16 at 11;000 ft. due to the multiple metro arrivals we feed at 11;000 ft. to the TRACON.
A Center Controller reported taking handoffs on two aircraft they did not recognize were converging at the same altitude due to stress from the government shutdown.