I am currently running into this issue where I have some constant data I'm trying to write to some DO lines. I want this data to be a constant array on my block diagram, so I create the array programmatically under the "my computer" target. I then change the indicator that is populated to a constant and move it to the FPGA. When I right click and set the array to be a fixed size, it replaces all my data with 0's. I propose the data should not be cleared if I set my fixed array size to be equal to the size which the array already is.