ID:890248
 
winset(src,"window.btnControl","is-checked=false")
world<<winget(src,"window.btnControl","is-checked")


Make a pushbox button with the name set to "btnControl", run the environment and push the button that will run the above code. It still returns true, when winset is obviously setting it to false. Bug?
I just opened up a test environment, put a pushbox and used this code. It returned false. Sounds like the issue is on your side, though I'm not sure what.
I just did my own test environment and it returns true for me. I'll zip it up and post a link to you guys.
The left button returns true every time and the right returns false every time. How strange.
The right button can be ignored. The test() verb is programmed for the left button only.
With pushbox buttons, it looks like one button is always expected to be "checked". If you change your buttons' appearances back to default, this is clearer.

To "uncheck" a pushbox button, you have to check another in its group:
client
verb
test()
winset(src,"default.button2","is-checked=true")
world<<winget(src,"default.testButton","is-checked")
All of the buttons start out "unchecked" when the world is ran, so it would make sense to be able to accomplish the same effect anytime at runtime as well. I guess the only way to achieve this would be to reset the interface via winset(src,null,"reset=true").

EDIT
Nope - not even that resets the pushboxes. it certainly looks ugly when a person goes through selecting a bunch of pushboxes, cancels the process to start over and returning to a bunch of pushboxes already pushed.
In response to Spunky_Girl
Spunky_Girl wrote:
All of the buttons start out "unchecked" when the world is ran

Are you sure? Running your demo environment, the right button starts out checked for me. It's easier to see if you give it the default background color.
Yeah I noticed it and made note of it in my feature request post.