Throughout most of the state's history, he was admired by the people and officials alike for his military and governance abilities, but his inexplicable failures in 398 helped to lead to the downfall of himself, his brother Murong Bao, and the Later Yan dynasty.
Murong Nong would renew his suggestion in 383 after Former Qin had failed in its attempt to conquer Jin and been severely weakened in the defeat at the Battle of Fei River.
Murong Chui agreed this time, and after receiving Fu Jiān's permission to go on a mission to try to pacify the northeastern empire, instead plotted rebellion.
Around the new year 386, Murong Nong stamped out all remaining Former Qin resistance in the You (幽州, modern Beijing, Tianjin, and northern Hebei) and Ping (平州, modern Liaoning) Provinces, including the rebel Yu Yan (餘巖), and further recovered some commanderies that Goguryeo had seized.
Murong Chui made him effective viceroy of You and Ping Provinces, in charge of the old Former Yan capital Longcheng (龍城, in modern Jinzhou, Liaoning), and he remained in that post for several years, apparently greatly favored by the people of the region.
However, Murong Nong immediately made the mistakes of collecting food for his troops—too much for the local population, then suffering from a famine, to support—and sending military officers to watch over non-Han tribes.
The people became resolved to revolt, and they sent messengers to Northern Wei, requesting Tuoba Gui to advance on Bing Province.
In late fall 396, he arrived at the capital of the province, Jinyang (晉陽, in modern Taiyuan, Shanxi), and when Murong Nong engaged Tuoba Gui in battle, Tuoba Gui defeated him, and he was forced to flee back to Zhongshan, but his wife and children were captured by Northern Wei and he himself was wounded.
Even with secret help from Lan Han the Prince of Dunqiu—Murong Chui's uncle—however, Duan was initially unsuccessful, until Murong Nong inexplicably, in fear of his life, surrendered to him.