Mendix 5.0 Button Not Displaying when checkmark is True

I had a button in 4.4.4 that displayed on the condition that a checkmark was True. It was working. After the upgrade to 5.0 the button does not display when the checkmark is True. Instead checking the box toggles other check marks on the form. A different attribute will toggle back and forth between checked and displaying the word "Yes", i.e. its value is not changing, only how it is displayed. Another attribute in the same form will toggle back and forth between unchecked and "No". These two toggles are occurring simultaneously when changing the checkmark that formerly controlled the visibility of the button, which as I say, does not display. Thanks for help.
1 answers

What webbrowser do you use? I see some strange behaviour with firefox version 22. So it could be that it is not mendix 5 related.