The Key x is down - execute following action - Not working reliably

[peternlewis]

The issue you are seeing is because you are looking for a state (key is down) but you really need the event (key is pressed), because the key only stays down a short time and if you do not check it while in the short time the key is down you will miss it. See:

Problems with "Pause until..." Action - trouble detecting key press/mouse click

Pause Until detects state, not events. You are wanting to detect the event of a key press or a mouse click, not detect the state of whether the key is down or the button is pressed. By default, in recent versions of Keyboard Maestro uses a Reduced CPU option, which means the check is happening less frequently which is why you are seeing the issue more often. You could turn off that option, but really that is just making the issue less prevalent. The problem is that the Pause Until only checks…

That has the same solution you need to reliably detect pressing a key (as opposed to detecting a key being down at a specific time, which is what you are doing).