Maybe take out the Master, bleed it on the bench, reinstall and bleed the Slave.
Use a Vacuum Gun type of bleeding device and make sure always to have a full reservoir.
Why I suggest it this way because if new then you would have to do it that way AND I have heard that when air gets in the master it isn’t easy to get out.
I am not a Mechanic just looking at this logically; there may be better ways to do this but I am just thinking out loud and a little bump helps to get things started.
4x4, 5sp, Std Cab, Stepside, E4 Red
4” Lift - Coil-Overs, 6” SkyJacker Leafs - No Blocks (Mistake)
31 Spline FX4 Rear Axle, 4.56s and OX Locker, Hurst Shifter w/Optional Stick and "Made by Grev" alignment adapter