DropdownButtonFormField selected item being clipped off

Within a DropdownButtonFormField with the following selectedItemBuilder:

selectedItemBuilder: (context) {
    return widget.items!.map<Widget>((item) {
        return Padding(
            padding: const EdgeInsets.only(top: 12.0),
            child: Text(
                item.name!,
                style: const TextStyle(fontSize: Sizes.p12),
            ),
        );
    }).toList();
},

The selected items are clipped off. Tried contentPadding parameter inside decoration's InputDecoration.

Having a Stack with clipBehavior set to Clip.none alleviates this issue. Also used Positioned instead of using Padding:

selectedItemBuilder: (context) {
    return widget.items.map<Widget>((item) {
        return Stack(
            clipBehavior: Clip.none,
            children: [
                Positioned(
                  bottom: -6,
                  child: Text(
                    item.name!,
                    style: const TextStyle(fontSize: Sizes.p12),
                  ),
                )
            ],
        );
    }).toList();
}

Edit: Full code requested, it's as shown below:

Container(
      height: 50.0,
      child: DropdownButtonFormField<Item>(
        value: widget.items,
        menuMaxHeight: 300.0,
        onChanged: (Item? item) {
          widget.updateCallback(item!);
        },
        isDense: true,
        isExpanded: true,
        selectedItemBuilder: (context) {
          return listOfValues!.map((item) {
            return Stack(
              clipBehavior: Clip.none,
              fit: StackFit.expand,
              children: [
                Positioned(
                  bottom: -6,
                  child: SizedBox(
                    width: 90.0,
                    child: FittedBox(
                      child: Text('${item.name!} - ${item.itemPercentage}%',
                      ),
                    ),
                  ),
                )
              ],
            );
          }).toList();
        },
        items: someList!
            .map((Choice choice) {
          return DropdownMenuItem<Item>(
            value: choice,
            child: Text(
              '${choice.name!} - ${choice.percemtage}%',
              overflow: TextOverflow.ellipsis,
              maxLines: 2,
            ),
          );
        }).toList(),
      ),
    )

Not sure if this runs as is as I had to strip some very specific preferences (colours, variable names etc.). But you get the general idea :).