Issue regarding the functional mri preprocessing and 1st level analysis script

I have written a script to preprocess and run 1st-level analysis of fMRI data for a single subject using SPM in matlab .The script runs fine (no errors).

But the resulting activation maps are showing activation in brain regions that shouldn’t be active (i.e., false positives or unexpected activations).

I have entered the correct onset times and durations, so i am not sure what’s going wrong.