MM HD The Dragon's Trap (Hard): floating lever doesn't function

[brell]

It is all very simple.

If Jack pulls a blue lever in this room the green lever will become unuseable until he re-enters the room.

If Jack enters this room from the room above via the LEFT ladder the green lever will be available.

Jack can also enter the room from the room to the left at the bottom ledge and the green lever will be available.