In an SVF system, you cannot directly enter the interface view on an AS and disable the interface. You need to run the shutdown interface interface-type interface-number command on the parent to disable the specified AS port.
Running this command can disable only an AS downlink port but not an AS uplink port. If an uplink port has been configured as a downlink fabric port, this port can be disabled.
If an AS is configured in the independent mode, the shutdown interface and undo shutdown interface commands do not take effect on the ports of this AS.