Can you explain what you mean by "hibox"? A screenshot might help.
What is the window resolution you are using? Have you tried changing the UI scaling option?
Ah, I'm sorry, that was a typo. I meant "hitbox," (https://en.wikipedia.org/wiki/Collision_detection#Hitbox) the size of the button that would actually respond to clicks. Even when a button has an area of, say, 20x20 pixels, it would not respond to clicks unless the mouse pointer was exactly on a certain single pixel in the middle of the button.
That doesn't sound right. You should be able to press any button by clicking anywhere on the button. This is the first time I'm hearing about such issue. Haven't been able to reproduce it on my machine, but I don't have a macos Catalina machine to test your setup.
Unfortunately, since I cannot reproduce the issue, I cannot fix it. I can refund your purchase if you want and if/when I'm able to test it on Catalina and fix it I can inform you to try it again.
Sorry for the inconvenience.
PS. Does the same thing happen in the online sandbox? http://dls.makingartstudios.com/sandbox/wasm
Seems fine in the online sandbox. (Chrome 79.0.3945.117)
I don't need a refund; This seems to work fine on my other machines (Windows and Linux) and my Mac is supposed to be for work anyway. :-)
After a little more investigation, it doesn't appear to be a problem of hitbox size, but there is definitely something going on that makes me have to try clicking at least 3-5 times before an action is taken. It may be sensitive to click, drag (deliberate or inadvertent drag), and release timing or something, but it makes it very difficult and almost unusable on this platform.