We faced similar problem in System version: 14.1(1j) with N9K-C93180YC-EX
When the console port on the back of the ACI leaf is connected via a cableto the port of Terminal Server CISCO ISR4321, the ACI Leaf refuses to startup and is stuck in loader, with front STS (Status) and ENV (Environment) LEDs blinking rapidly in orange.
Unplugging the ethernet cable on the back Console port of the Leaf releases the startup and the switch successfully starts. By doing that, the Leaf starts up and front LEDs turn to fix orange, then green after 2 minutes
