The home position is not 0,0 it is 0,450 this is because the bottom left is the origin. The reason for this is homing to the back left means the laser is out of the way and you can access the bed.
to make that 0,0 you would need to flip the Y axis which would cause jobs to be upside down or work in the -Y space, but this had issues too but maybe is possible to add for the future.
I am not sure whats going wrong at the moment?
When you click home is it moving to the back left?
ALARM homing fail, have not seen this before?
Could you make a film on your phone or somthing to show what it is doing?