On 29 February 2020, an Airbus A320 inbound to Delhi lost separation against an outbound A320 from Delhi on a reciprocal track and the conflict was resolved by TCAS RA activation. The Investigation found that the inbound aircraft had correctly read back its descent clearance but then set a different selected altitude. Air Traffic Control had not reacted to the annunciated conflict alert and was unable to resolve it when the corresponding warning followed and it was noted that convective weather meant most aircraft were requesting deviations from their standard routes which was leading to abnormally complex workload.