I came across this story via an RTÉ article¹ which I was going to submit as it’s unusual and commendable for a mainstream media articles to link directly to the source paper,
Modern human incursion into Neanderthal territories 54,000 years ago at Mandrin, France². The RTÉ article also describes the differences between Mousterian (Neanderthal) and Neronian (modern humans) technology which is relevant to the alternating occupation hypothesis.
In the end, I figured this Science article is the more nuanced and informative, e.g., it includes a description of fuliginochronology (a novel dating technique that I hadn’t heard of).
¹ https://www.rte.ie/news/world/2022/0210/1278948-child-tooth/
² https://www.science.org/doi/10.1126/sciadv.abj9496