Shikkapow

I have spent a few hours trying to figure out how to get the support blocker to work. I use the tool, reshape, etc, and then slice and save as stl file. Every time I go to print, it shows a huge solid cube in the print software. Im using ultimaker cura 4.5.0 as the slicer and creality 1.2.3 as my feed software for the printer. doesnt matter which 3d model software i use, the block (that is supposed to be the support blocker shows up as a solid block