Homing script mach3 nvemV2

Hi All
I am having trouble with homing/ squaring my Y axis on my gantry mill,
System is a NVEM V2 5axis,
Have two independent Z axis, Z and A, and X axis.
Y axis is gantry and slaved to B axis all works as expected my issue is when trying to home Y axis the slave B axis does not disconnect and does not recognise home switch, home switch is independent and activates can be seen in diagnostics screen but will not travel off or to the switch only travels same as Y axis.
Does not seem to make any difference if in general config settings, home slave with master is checked or unchecked.
Have tried several DoButton combinations on the Ref All Home button:
DoButton (24) Z axis M3 home switch
(25) A axis M4 home switch
(22) X axis M1 home switch
(23) Y axis M2 home switch
(27) B axis M5 home switch, same result with or without this line.

DoButton (24) Z
(25) A
(22) X
RefCombination(18) Y&B axis’s with same result as above.
Have included a video of my diagnostics screen when homing so can see the sequence and that the B axis will not home independent from Y.
Have found the section from programmers manual on coupling and uncoupling slaves but do not know where or how to input this in. If some one could provide some assistance with this that would be great.

sorry wont let me up load the video.

Your controller may not support proper slaved homing.

Thanks for responding Gerry, was hoping it was just going to be a programing issue.