Star Trek: Enterprise had a subtle reference to Star Trek: Voyager in one episode of season 2. Despite airing one right after the other in the Star Trek timeline, Enterprise and Voyager had very little in common. Voyager explored the adventures of the USS Voyager’s crew in the Delta Quadrant during the 2370s, while Enterprise catapulted the franchise back to the beginning of Starfleet, showcasing the missions of the first starship Enterprise in the 22nd century. However, all Star Trek shows are connected, and Enterprise still found a way to reference its predecessors while maintaining its prequel status.
https://screenrant.com/star-trek-voyager-enterprise-bride-of-chaotica-crossover/