Seems to do with click duration to me, as a quick click works better. Having ahk send a click seems to fix and allow for consistent registering no matter how long you hold trigger with the following ahk:
Lbutton::
Click
Return
Seems to solve above issue, but when skipping info screens, you have to hold mouse button, so that no longer works as it only sends a short click, no matter how long you hold. I found the Enter key also activates the skipping feature. So, you can either bind a different gun button to Enter and use it for skipping, or have left button send click and hold enter button for duration of trigger press, using ahk below. Make sure to only run this with game, as if this script is running then you double click the game, it will open the game several times and you would not want this running when clicking around in windows OS
lbutton::
click
send, {enter down}
KeyWait, LButton
send, {enter up}
return
I did my testing with demulshooter running as admin, but game and script NOT running as admin