After further research, I found the toggle button style being inconsistent, or 'unreliable' as you have stated. When the application first runs, the toggle buttons that are located in subforms display correctly (rounded, two colors, etc). If  I switch to Design View and then switch back to Form View, the toggles buttons revert back to the old style (squared, no color, etc). So in the end, the toggle buttons will display correctly each time the user runs the application. And that is fine with me.

Thank you

---

Reply from Richard Rost:

Sounds good. Like I said, I haven't noticed this behavior, but what you're saying makes sense.