I hate to admit that I'm finding working in Layout mode in v12 to be very frustrating for a number of reasons.
My current stumbling block is a button hover issue. I have a box ( created with the rectangle tool) and it has a text label centered on it. It's set as a button. When the operator hovers a mouse over the box the Hover state kicks in and looks right. However, when the operator hovers the mouse over the text the rectangle is no longer the hovered object so the label goes into its Hover state and the box goes to Normal state.
I've tried a number of groupings and ungroupings. Using the button tool works for this but I don't have the control that I need using that.
1. Ungroup the box / text
2. Apply the hover state (as you have) to the box
3. Apply the button to the box (not the text)
4. Re-group if required
Because the text is a button (im assuming you created the button whilst grouped), it has its own hover states which are interfering with the box.
Hope this helps.