(VX) Window visibility

I remember having this problem before on a different script, but I'm still not getting much in the way of success with it.

When trying to select an invalid option (in this case choosing a skill from the list of skills) I want to get a window to open/become visible to display a message and wait for a button to pressed before going closed/invisible. During this message being displayed I intend to make the skill window inactive. I can get the message to display just fine, getting it to go away is a different matter. I set up an input check whilst the window is visible and it now doesn't show at all. It definitely processes it - I checked by getting it to p out to windows when it arrives at the method - it's just processing so fast the message window appears and leaves almost instantly.

I was using Input.trigger? and have tried press? as well (not tried repeat? as I doubt that'd work any better). I don't want to have to make a new scene for the sake of a single message window.

Since there seems to be a lack of being able to halt processes, I'm missing something that'll get it to stay until I tell it to go. Any pointers on what to do would be appreciated.