I own a 2017 Kia Sportage with a 1.7 diesel engine, which has accumulated 80,000 kilometres. The fuel filter was replaced 6 weeks ago at 75,000 miles. Despite no issues during normal use on Friday, the engine started idling roughly and almost cutting out when I started it in the evening to go to the shop. When I slightly revved the engine, it did not respond immediately but eventually started running normally. This rough idling now occurs every time I start the engine, regardless of whether it is at running temperature or cold. If I don't rev the engine before setting off, it lacks power when accelerating, but then surges and drives normally. The AA conducted a thorough inspection and test drive but were unable to identify any defects, even when the vehicle was turned off and restarted. Another observation I have made is that the stop-start feature no longer activates, although its functionality has always been inconsistent. Has anybody else had similar issues? Thank you in advance.