Printrbot simple metal not auto leveling
See if you can check what the starting G-Code is. I havn't used Cura but what I think has changed for you is that your new software is homing just using the G28 command and not the G29 command.

I think if you can look into your slicer settings you will find an option to change what the starting gcode is and you will probably want to change it to something like this

G28 X0 Y0
G28 Z0
G29