Problem:

I don't get the reaction I am expecting from my radio button default

Some times I open the window and it is the default sometimes I open the window and it's something else.

Resolution:

Your radio button is clashing with another radio button with the same first name as part of a spacey name.

The object name "jack jill"  is evaluated to jack.

The jack object is clashing with another jack object.

Spacey name objects are not permitted.