Hey there, one observation... that action would resize/reposition the front window the to left half of the screen, not the upper-left corner.
That being said, does it work if you trigger the macro/action a second time? There are documented cases of the manipulate a window action not properly moving a window.
Links to similar issues (click to expand/collapse)
Move and Resize Windows Works Sporadically, One Step at a Time - Questions & Suggestions - Keyboard Maestro Discourse
Prompt for User Input Window Not Appearing Even Though It Is Triggered - Questions & Suggestions - Keyboard Maestro Discourse
Possible Bug: Manipulate a Window Interacts Differently (And Unreliably) With Different Applications - Questions & Suggestions - Keyboard Maestro Discourse
If possible, post your macro, or at least a screenshot of the entire macro and a screen recording of the issue. Otherwise it’s unlikely we’ll be able to help.
-Chris